64644440646402 has 12 divisors (see below), whose sum is σ = 140062954733910. Its totient is φ = 21548146882128.

The previous prime is 64644440646377. The next prime is 64644440646413. The reversal of 64644440646402 is 20464604444646.

64644440646402 is a `hidden beast` number, since 6 + 46 + 44 + 440 + 64 + 64 + 0 + 2 = 666.

It can be written as a sum of positive squares in only one way, i.e., 63604915622361 + 1039525024041 = 7975269^2 + 1019571^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1795678906827 + ... + 1795678906862.

Almost surely, 2^{64644440646402} is an apocalyptic number.

64644440646402 is an abundant number, since it is smaller than the sum of its proper divisors (75418514087508).

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

64644440646402 is a wasteful number, since it uses less digits than its factorization.

64644440646402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3591357813697 (or 3591357813694 counting only the distinct ones).

The product of its (nonzero) digits is 42467328, while the sum is 54.

The spelling of 64644440646402 in words is "sixty-four trillion, six hundred forty-four billion, four hundred forty million, six hundred forty-six thousand, four hundred two".