21337523256 has 64 divisors (see below), whose sum is σ = 63066585600. Its totient is φ = 5886211968.

The previous prime is 21337523239. The next prime is 21337523257. The reversal of 21337523256 is 65232573312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21337523257) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 2184940 + ... + 2194683.

It is an arithmetic number, because the mean of its divisors is an integer number (985415400).

Almost surely, 2^21337523256 is an apocalyptic number.

It is an amenable number.

21337523256 is an abundant number, since it is smaller than the sum of its proper divisors (41729062344).

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

21337523256 is a wasteful number, since it uses less digits than its factorization.

21337523256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4379668 (or 4379664 counting only the distinct ones).

The product of its digits is 226800, while the sum is 39.

The spelling of 21337523256 in words is "twenty-one billion, three hundred thirty-seven million, five hundred twenty-three thousand, two hundred fifty-six".