21157504170 has 32 divisors (see below), whose sum is σ = 55394193600. Its totient is φ = 5129091840.

The previous prime is 21157504117. The next prime is 21157504261. The reversal of 21157504170 is 7140575112.

It is a super-4 number, since 4×21157504170⁴ (a number of 42 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

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, 32056495 + ... + 32057154.

It is an arithmetic number, because the mean of its divisors is an integer number (1731068550).

Almost surely, 2^21157504170 is an apocalyptic number.

21157504170 is an abundant number, since it is smaller than the sum of its proper divisors (34236689430).

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

21157504170 is a wasteful number, since it uses less digits than its factorization.

21157504170 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64113670.

The product of its (nonzero) digits is 9800, while the sum is 33.

The spelling of 21157504170 in words is "twenty-one billion, one hundred fifty-seven million, five hundred four thousand, one hundred seventy".