21216015265400 has 48 divisors (see below), whose sum is σ = 49327541179800. Its totient is φ = 8486353514880.

The previous prime is 21216015265369. The next prime is 21216015265433. The reversal of 21216015265400 is 456251061212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 56696111 + ... + 57069089.

Almost surely, 2^{21216015265400} is an apocalyptic number.

21216015265400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21216015265400 is an abundant number, since it is smaller than the sum of its proper divisors (28111525914400).

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

21216015265400 is a wasteful number, since it uses less digits than its factorization.

21216015265400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 657408 (or 657399 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 35.

The spelling of 21216015265400 in words is "twenty-one trillion, two hundred sixteen billion, fifteen million, two hundred sixty-five thousand, four hundred".