21221057406504 has 32 divisors (see below), whose sum is σ = 55359280192320. Its totient is φ = 6766134245376.

The previous prime is 21221057406473. The next prime is 21221057406539. The reversal of 21221057406504 is 40560475012212.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19221971737 + ... + 19221972840.

It is an arithmetic number, because the mean of its divisors is an integer number (1729977506010).

Almost surely, 2^{21221057406504} is an apocalyptic number.

21221057406504 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21221057406504 is an abundant number, since it is smaller than the sum of its proper divisors (34138222785816).

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

21221057406504 is a wasteful number, since it uses less digits than its factorization.

21221057406504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38443944609 (or 38443944605 counting only the distinct ones).

The product of its (nonzero) digits is 134400, while the sum is 39.

The spelling of 21221057406504 in words is "twenty-one trillion, two hundred twenty-one billion, fifty-seven million, four hundred six thousand, five hundred four".