645623718264 has 48 divisors (see below), whose sum is σ = 1998359129520. Its totient is φ = 184463919360.

The previous prime is 645623718253. The next prime is 645623718371. The reversal of 645623718264 is 462817326546.

645623718264 is a `hidden beast` number, since 6 + 4 + 5 + 6 + 2 + 371 + 8 + 264 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 645623718264.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 640499217 + ... + 640500224.

It is an arithmetic number, because the mean of its divisors is an integer number (41632481865).

Almost surely, 2^645623718264 is an apocalyptic number.

It is an amenable number.

645623718264 is an abundant number, since it is smaller than the sum of its proper divisors (1352735411256).

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

645623718264 is a wasteful number, since it uses less digits than its factorization.

645623718264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1280999460 (or 1280999453 counting only the distinct ones).

The product of its digits is 11612160, while the sum is 54.

The spelling of 645623718264 in words is "six hundred forty-five billion, six hundred twenty-three million, seven hundred eighteen thousand, two hundred sixty-four".