Not relevant to the numerology, but to Kali Age literature more broadly, is the actual question of: what does it mean? Why does Kali Age literature arise, and what is it's purpose in the Brāhmaṇa state of affairs. It seems clear to me that the Kali Yuga, for Brāhmaṇas, was almost synonymous with the Buddhist era. The rise and flourishing of Buddhism, for the orthodox Brāhmaṇa, meant the decline of the pure varṇāśramadharma (relevant to the thread for the obvious racial connotations too):
Verardi, Hardships and Downfall of Buddhism in India, 81. wrote:In the alternation of kings and dynasties that followed the downfall of the Mauryas - an issue to which modern historians have attached little importance - we can discern the attempts to translate into terms of political power the antinomial model of society or, from the Brahmanical point of view, the rising and setting up, in successive waves, of the Kali age. The memory of Aśoka, always kept alive in Buddhist countries, was to disappear from the horizon of Indian history not because of an inexplicable refusal or inability of the Brahmanical elites to keep the record of past and present events in chronicals and histories, but because of a targeted hostility to handing down whatever history was not their own.
An example of the Kali age as being distinctive of the Buddhist era, with the Buddhist rejection of varṇā and Yajñas, is exemplified by the Vāyu Purāṇa:
Vāyu Purāṇa, I.58.34-70 wrote:In Kali Yuga, people do not accept the authority of Smṛtis. ... There is danger and fear to people owing to wrong performance of sacrifices, neglect of Vedic studies ... The Brāhmaṇas do not perform Yajñas [Note that a great proportion of Buddhists would come from Brāhmaṇa families] ... Low-bown and insignificant persons have contact with Brāhmaṇas in sharing beds, seats, and food in Kali Age. Kings are mainly śūdras [reference to the Nanda dynasty, sometimes considered Buddhist] propagating hertic ideas. People never hesitate to kill a child in the womb [a common Brāhmaṇa allegory for śramaṇism, where renunciation of family life deprives one's family of rightful children] ... The kings do not belong to the Kṣatriya clan [ironic considering many Brāhmaṇas were fond of taking over kingship themselves]. Vaiśyas maintain themselves with the help of śūdras. The noble Brāhmaṇas perform obeisance to śūdras at the end of the Kali Age. ... In this base Yuga, people will have trading propensity [of course referring to Buddhists, who made up the vast majority of the merchant class]. ... The whole society abounds in heretics of foul conduct and activity with their false appearance. Men will be in a minority and women will be many, when the end of the Kali Yuga is imminent. ... When the close of the Yuga is imminent, śūdras exhibiting their white teeth [relevant to this thread, note the racial connotations here - being darker skinned, their teeth appear whiter], with clean shaven heads and wearing ochre-coloured robes will perform sacred, rites, proclaiming that they have conquered the sense organs. ... The Vedas will be seen in some places and not seen in some places. ... Yajñas are forsaken when Dharma receives a setback. There will be many types of heretics like wearers of ochre-coloured robes (Buddhists), Jainas, and Kāpālikas. ... Heretics antagonistic to the discipline and arrangement of different castes and stages of life will be born. When Kali Yuga sets in, the Vedas will not be studied. śūdras will be experts and authorities in the affairs of Dharma. ... People will kill and destroy children in wombs. ... The Vedas will be seen somewhere and not seen in some places. When Dharma is harassed Yajñas are forsaken.
And the Bhāgavata's Viṣṇudharma Upapurāṇa:
Viṣṇudharma Upapurāṇa in Introduction to the History of Indian Buddhism, Eugène Burnouf, 2010, p. 395. wrote:At the time, the vile śūdras, bearing the signs of mendicancy, will not serve the twice-born people, nor will they practice their own dharma. Some will become Utcokas, Saugatas, Mahāyānists, and the heretical Kāpalicas and Bhikṣus, while other wicked śūdras will turn śākyas, śravakas, nirgranthas and siddhaputras in the Kali age. Turning wandering mendicants the villainous śūdras will undergo no physical purification, have crooked nature, and habitually live on food prepared by others.
Also, Asuras are an analogy for Buddhists in many Brāhmaṇa writings and inscriptions, and Viṣṇu and śiva are commonly depicted as emerging IN the Kali Age, for the destruction over Asuras. On P. 224, Verardi shows an inscription where not only are Buddhists referenced as being these Asuras defeated by śiva in the Kali Age, but the associated panel depicts śiva, surrounded by lions (metaphor for killing Buddhists), on top of an elephant head (allegorical Buddhist). There are so many instances of things like this that it because very apparent what the message of "Kali Age" literature is: down with Buddhism, death to the Bauddhas.