21260656624 has 20 divisors (see below), whose sum is σ = 41333120136. Its totient is φ = 10594044992.

The previous prime is 21260656609. The next prime is 21260656631. The reversal of 21260656624 is 42665606212.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2262874 + ... + 2272249.

Almost surely, 2^21260656624 is an apocalyptic number.

It is an amenable number.

21260656624 is a deficient number, since it is larger than the sum of its proper divisors (20072463512).

21260656624 is a wasteful number, since it uses less digits than its factorization.

21260656624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4535424 (or 4535418 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 40.

The spelling of 21260656624 in words is "twenty-one billion, two hundred sixty million, six hundred fifty-six thousand, six hundred twenty-four".