636442625521640 has 128 divisors (see below), whose sum is σ = 1638214212096000. Its totient is φ = 217989261127680.

The previous prime is 636442625521631. The next prime is 636442625521657. The reversal of 636442625521640 is 46125526244636.

It is a Harshad number since it is a multiple of its sum of digits (56).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6920290937 + ... + 6920382903.

It is an arithmetic number, because the mean of its divisors is an integer number (12798548532000).

Almost surely, 2^{636442625521640} is an apocalyptic number.

It is an amenable number.

636442625521640 is an abundant number, since it is smaller than the sum of its proper divisors (1001771586574360).

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

636442625521640 is a wasteful number, since it uses less digits than its factorization.

636442625521640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116595 (or 116591 counting only the distinct ones).

The product of its (nonzero) digits is 49766400, while the sum is 56.

The spelling of 636442625521640 in words is "six hundred thirty-six trillion, four hundred forty-two billion, six hundred twenty-five million, five hundred twenty-one thousand, six hundred forty".