21252565064400 has 120 divisors (see below), whose sum is σ = 68275244655264. Its totient is φ = 5651018150400.

The previous prime is 21252565064389. The next prime is 21252565064429. The reversal of 21252565064400 is 446056525212.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-2 number, since 2×21252565064400² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25103011 + ... + 25935810.

Almost surely, 2^{21252565064400} is an apocalyptic number.

21252565064400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21252565064400 is an abundant number, since it is smaller than the sum of its proper divisors (47022679590864).

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

21252565064400 is a wasteful number, since it uses less digits than its factorization.

21252565064400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51039189 (or 51039178 counting only the distinct ones).

The product of its (nonzero) digits is 576000, while the sum is 42.

The spelling of 21252565064400 in words is "twenty-one trillion, two hundred fifty-two billion, five hundred sixty-five million, sixty-four thousand, four hundred".