21621664012760 has 64 divisors (see below), whose sum is σ = 56733229224000. Its totient is φ = 7413141942528.

The previous prime is 21621664012703. The next prime is 21621664012843. The reversal of 21621664012760 is 6721046612612.

It is a congruent number.

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, 787947797 + ... + 787975236.

It is an arithmetic number, because the mean of its divisors is an integer number (886456706625).

Almost surely, 2^{21621664012760} is an apocalyptic number.

21621664012760 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21621664012760 is an abundant number, since it is smaller than the sum of its proper divisors (35111565211240).

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

21621664012760 is a wasteful number, since it uses less digits than its factorization.

21621664012760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1575923065 (or 1575923047 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 44.

The spelling of 21621664012760 in words is "twenty-one trillion, six hundred twenty-one billion, six hundred sixty-four million, twelve thousand, seven hundred sixty".