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Last digits of divisors

Problem 474

Published on 01 June 2014 at 07:00 am [Server Time]

For a positive integer n and digits d, we define F(n, d) as the number of the divisors of n whose last digits equal d.
For example, F(84, 4) = 3. Among the divisors of 84 (1, 2, 3, 4, 6, 7, 12, 14, 21, 28, 42, 84), three of them (4, 14, 84) have the last digit 4.

We can also verify that F(12!, 12) = 11 and F(50!, 123) = 17888.

Find F(106!, 65432) modulo (1016 + 61).


Answer not yet available
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