21313645264 has 20 divisors (see below), whose sum is σ = 42627291520. Its totient is φ = 10313053920.

The previous prime is 21313645259. The next prime is 21313645271. The reversal of 21313645264 is 46254631312.

21313645264 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21485034 + ... + 21486025.

It is an arithmetic number, because the mean of its divisors is an integer number (2131364576).

Almost surely, 2^21313645264 is an apocalyptic number.

It is an amenable number.

21313645264 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21313645264 is a wasteful number, since it uses less digits than its factorization.

21313645264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42971098 (or 42971092 counting only the distinct ones).

The product of its digits is 103680, while the sum is 37.

The spelling of 21313645264 in words is "twenty-one billion, three hundred thirteen million, six hundred forty-five thousand, two hundred sixty-four".