642015861968 has 20 divisors (see below), whose sum is σ = 1339590789348. Its totient is φ = 296315013120.

The previous prime is 642015861931. The next prime is 642015862009. The reversal of 642015861968 is 869168510246.

It can be written as a sum of positive squares in 2 ways, for example, as 281141731984 + 360874129984 = 530228^2 + 600728^2 .

It is a congruent number.

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, 1543307153 + ... + 1543307568.

Almost surely, 2^642015861968 is an apocalyptic number.

It is an amenable number.

642015861968 is an abundant number, since it is smaller than the sum of its proper divisors (697574927380).

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

642015861968 is a wasteful number, since it uses less digits than its factorization.

642015861968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3086614742 (or 3086614736 counting only the distinct ones).

The product of its (nonzero) digits is 4976640, while the sum is 56.

The spelling of 642015861968 in words is "six hundred forty-two billion, fifteen million, eight hundred sixty-one thousand, nine hundred sixty-eight".