21621451514464 has 24 divisors (see below), whose sum is σ = 42689201839200. Its totient is φ = 10779749460096.

The previous prime is 21621451514461. The next prime is 21621451514473. The reversal of 21621451514464 is 46441515412612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21621451514461) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 967997944 + ... + 968020279.

It is an arithmetic number, because the mean of its divisors is an integer number (1778716743300).

Almost surely, 2^{21621451514464} is an apocalyptic number.

It is an amenable number.

21621451514464 is a deficient number, since it is larger than the sum of its proper divisors (21067750324736).

21621451514464 is a wasteful number, since it uses less digits than its factorization.

21621451514464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1936018582 (or 1936018574 counting only the distinct ones).

The product of its digits is 921600, while the sum is 46.

The spelling of 21621451514464 in words is "twenty-one trillion, six hundred twenty-one billion, four hundred fifty-one million, five hundred fourteen thousand, four hundred sixty-four".