21507532044400 has 60 divisors (see below), whose sum is σ = 51899475232152. Its totient is φ = 8565114046720.

The previous prime is 21507532044347. The next prime is 21507532044407. The reversal of 21507532044400 is 444023570512.

It is a self number, because there is not a number n which added to its sum of digits gives 21507532044400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21507532044407) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 118342747 + ... + 118524346.

Almost surely, 2^{21507532044400} is an apocalyptic number.

21507532044400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21507532044400 is an abundant number, since it is smaller than the sum of its proper divisors (30391943187752).

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

21507532044400 is a wasteful number, since it uses less digits than its factorization.

21507532044400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236867338 (or 236867327 counting only the distinct ones).

The product of its (nonzero) digits is 134400, while the sum is 37.

The spelling of 21507532044400 in words is "twenty-one trillion, five hundred seven billion, five hundred thirty-two million, forty-four thousand, four hundred".