21115763264 has 14 divisors (see below), whose sum is σ = 41901592854. Its totient is φ = 10557881600.

The previous prime is 21115763219. The next prime is 21115763269. The reversal of 21115763264 is 46236751112.

It can be written as a sum of positive squares in only one way, i.e., 21080716864 + 35046400 = 145192^2 + 5920^2 .

It is not an unprimeable number, because it can be changed into a prime (21115763269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 164966837 + ... + 164966964.

Almost surely, 2^21115763264 is an apocalyptic number.

It is an amenable number.

21115763264 is a deficient number, since it is larger than the sum of its proper divisors (20785829590).

21115763264 is an equidigital number, since it uses as much as digits as its factorization.

21115763264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329933813 (or 329933803 counting only the distinct ones).

The product of its digits is 60480, while the sum is 38.

The spelling of 21115763264 in words is "twenty-one billion, one hundred fifteen million, seven hundred sixty-three thousand, two hundred sixty-four".