645109356972 has 96 divisors (see below), whose sum is σ = 1532558540800. Its totient is φ = 211180919040.

The previous prime is 645109356943. The next prime is 645109357003. The reversal of 645109356972 is 279653901546.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 64836654 + ... + 64846602.

Almost surely, 2^645109356972 is an apocalyptic number.

It is an amenable number.

645109356972 is an abundant number, since it is smaller than the sum of its proper divisors (887449183828).

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

645109356972 is a wasteful number, since it uses less digits than its factorization.

645109356972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10511 (or 10509 counting only the distinct ones).

The product of its (nonzero) digits is 12247200, while the sum is 57.

The spelling of 645109356972 in words is "six hundred forty-five billion, one hundred nine million, three hundred fifty-six thousand, nine hundred seventy-two".