21664415570774 has 16 divisors (see below), whose sum is σ = 32971486868640. Its totient is φ = 10674187554240.

The previous prime is 21664415570773. The next prime is 21664415570821. The reversal of 21664415570774 is 47707551446612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21664415570771) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 66739082 + ... + 67062909.

It is an arithmetic number, because the mean of its divisors is an integer number (2060717929290).

Almost surely, 2^{21664415570774} is an apocalyptic number.

21664415570774 is a deficient number, since it is larger than the sum of its proper divisors (11307071297866).

21664415570774 is a wasteful number, since it uses less digits than its factorization.

21664415570774 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133803175.

The product of its (nonzero) digits is 39513600, while the sum is 59.

The spelling of 21664415570774 in words is "twenty-one trillion, six hundred sixty-four billion, four hundred fifteen million, five hundred seventy thousand, seven hundred seventy-four".