21626621564540 has 96 divisors (see below), whose sum is σ = 45688757452800. Its totient is φ = 8598828948480.

The previous prime is 21626621564519. The next prime is 21626621564549. The reversal of 21626621564540 is 4546512662612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21626621564549) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11509643321 + ... + 11509645199.

It is an arithmetic number, because the mean of its divisors is an integer number (475924556800).

Almost surely, 2^{21626621564540} is an apocalyptic number.

21626621564540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21626621564540 is an abundant number, since it is smaller than the sum of its proper divisors (24062135888260).

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

21626621564540 is a wasteful number, since it uses less digits than its factorization.

21626621564540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5275 (or 5273 counting only the distinct ones).

The product of its (nonzero) digits is 4147200, while the sum is 50.

The spelling of 21626621564540 in words is "twenty-one trillion, six hundred twenty-six billion, six hundred twenty-one million, five hundred sixty-four thousand, five hundred forty".