21074172660 has 72 divisors (see below), whose sum is σ = 63940705920. Its totient is φ = 5618397888.

The previous prime is 21074172631. The next prime is 21074172709. The reversal of 21074172660 is 6627147012.

21074172660 is a `hidden beast` number, since 210 + 7 + 417 + 26 + 6 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 870601 + ... + 894479.

It is an arithmetic number, because the mean of its divisors is an integer number (888065360).

Almost surely, 2^21074172660 is an apocalyptic number.

21074172660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21074172660 is an abundant number, since it is smaller than the sum of its proper divisors (42866533260).

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

21074172660 is a wasteful number, since it uses less digits than its factorization.

21074172660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28797 (or 28792 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 36.

The spelling of 21074172660 in words is "twenty-one billion, seventy-four million, one hundred seventy-two thousand, six hundred sixty".