645102020656 has 40 divisors (see below), whose sum is σ = 1312282995120. Its totient is φ = 306780359424.

The previous prime is 645102020623. The next prime is 645102020681. The reversal of 645102020656 is 656020201546.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10344331 + ... + 10406506.

It is an arithmetic number, because the mean of its divisors is an integer number (32807074878).

Almost surely, 2^645102020656 is an apocalyptic number.

It is an amenable number.

645102020656 is an abundant number, since it is smaller than the sum of its proper divisors (667180974464).

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

645102020656 is a wasteful number, since it uses less digits than its factorization.

645102020656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20750941 (or 20750935 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 37.

The spelling of 645102020656 in words is "six hundred forty-five billion, one hundred two million, twenty thousand, six hundred fifty-six".