644754564135 has 48 divisors (see below), whose sum is σ = 1226219668128. Its totient is φ = 310801248000.

The previous prime is 644754564121. The next prime is 644754564143. The reversal of 644754564135 is 531465457446.

644754564135 is a `hidden beast` number, since 6 + 4 + 4 + 7 + 545 + 64 + 1 + 35 = 666.

It is not a de Polignac number, because 644754564135 - 2⁷ = 644754564007 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3678916 + ... + 3850185.

It is an arithmetic number, because the mean of its divisors is an integer number (25546243086).

Almost surely, 2^644754564135 is an apocalyptic number.

644754564135 is a deficient number, since it is larger than the sum of its proper divisors (581465103993).

644754564135 is a wasteful number, since it uses less digits than its factorization.

644754564135 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7529296 (or 7529293 counting only the distinct ones).

The product of its digits is 24192000, while the sum is 54.

The spelling of 644754564135 in words is "six hundred forty-four billion, seven hundred fifty-four million, five hundred sixty-four thousand, one hundred thirty-five".