645926736040 has 16 divisors (see below), whose sum is σ = 1453335156180. Its totient is φ = 258370694400.

The previous prime is 645926736031. The next prime is 645926736067. The reversal of 645926736040 is 40637629546.

It can be written as a sum of positive squares in 2 ways, for example, as 537884360836 + 108042375204 = 733406^2 + 328698^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8074084161 + ... + 8074084240.

Almost surely, 2^645926736040 is an apocalyptic number.

It is an amenable number.

645926736040 is an abundant number, since it is smaller than the sum of its proper divisors (807408420140).

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

645926736040 is a wasteful number, since it uses less digits than its factorization.

645926736040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16148168412 (or 16148168408 counting only the distinct ones).

The product of its (nonzero) digits is 6531840, while the sum is 52.

The spelling of 645926736040 in words is "six hundred forty-five billion, nine hundred twenty-six million, seven hundred thirty-six thousand, forty".