21621531660204 has 48 divisors (see below), whose sum is σ = 57871757664000. Its totient is φ = 6154615484736.

The previous prime is 21621531660191. The next prime is 21621531660251. The reversal of 21621531660204 is 40206613512612.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 478414554 + ... + 478459745.

It is an arithmetic number, because the mean of its divisors is an integer number (1205661618000).

Almost surely, 2^{21621531660204} is an apocalyptic number.

It is an amenable number.

21621531660204 is an abundant number, since it is smaller than the sum of its proper divisors (36250226003796).

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

21621531660204 is a wasteful number, since it uses less digits than its factorization.

21621531660204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 956874582 (or 956874580 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 39.

The spelling of 21621531660204 in words is "twenty-one trillion, six hundred twenty-one billion, five hundred thirty-one million, six hundred sixty thousand, two hundred four".