21249656992 has 24 divisors (see below), whose sum is σ = 41840385300. Its totient is φ = 10623527424.

The previous prime is 21249656983. The next prime is 21249657001. The reversal of 21249656992 is 29965694212.

It is an interprime number because it is at equal distance from previous prime (21249656983) and next prime (21249657001).

It can be written as a sum of positive squares in 2 ways, for example, as 20827107856 + 422549136 = 144316^2 + 20556^2 .

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, 258634 + ... + 330742.

Almost surely, 2^21249656992 is an apocalyptic number.

It is an amenable number.

21249656992 is a deficient number, since it is larger than the sum of its proper divisors (20590728308).

21249656992 is an equidigital number, since it uses as much as digits as its factorization.

21249656992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81328 (or 81320 counting only the distinct ones).

The product of its digits is 4199040, while the sum is 55.

The spelling of 21249656992 in words is "twenty-one billion, two hundred forty-nine million, six hundred fifty-six thousand, nine hundred ninety-two".