645307165044 has 30 divisors (see below), whose sum is σ = 1686960398354. Its totient is φ = 215102388240.

The previous prime is 645307165031. The next prime is 645307165123. The reversal of 645307165044 is 440561703546.

645307165044 is a `hidden beast` number, since 6 + 4 + 530 + 71 + 6 + 5 + 0 + 44 = 666.

It can be written as a sum of positive squares in only one way, i.e., 626266476900 + 19040688144 = 791370^2 + 137988^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 995844067 + ... + 995844714.

Almost surely, 2^645307165044 is an apocalyptic number.

It is an amenable number.

645307165044 is an abundant number, since it is smaller than the sum of its proper divisors (1041653233310).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

645307165044 is a wasteful number, since it uses less digits than its factorization.

645307165044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1991688797 (or 1991688786 counting only the distinct ones).

The product of its (nonzero) digits is 1209600, while the sum is 45.

The spelling of 645307165044 in words is "six hundred forty-five billion, three hundred seven million, one hundred sixty-five thousand, forty-four".