21365555263172 has 96 divisors (see below), whose sum is σ = 40127936755200. Its totient is φ = 9923359444992.

The previous prime is 21365555263051. The next prime is 21365555263177. The reversal of 21365555263172 is 27136255556312.

It is not an unprimeable number, because it can be changed into a prime (21365555263177) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3324340223 + ... + 3324346649.

It is an arithmetic number, because the mean of its divisors is an integer number (417999341200).

Almost surely, 2^{21365555263172} is an apocalyptic number.

It is an amenable number.

21365555263172 is a deficient number, since it is larger than the sum of its proper divisors (18762381492028).

21365555263172 is a wasteful number, since it uses less digits than its factorization.

21365555263172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8305 (or 8303 counting only the distinct ones).

The product of its digits is 11340000, while the sum is 53.

The spelling of 21365555263172 in words is "twenty-one trillion, three hundred sixty-five billion, five hundred fifty-five million, two hundred sixty-three thousand, one hundred seventy-two".