21731664311375 has 64 divisors (see below), whose sum is σ = 28962884396160. Its totient is φ = 16250363136000.

The previous prime is 21731664311351. The next prime is 21731664311381. The reversal of 21731664311375 is 57311346613712.

It is not a de Polignac number, because 21731664311375 - 2²⁴ = 21731647534159 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 16996985 + ... + 18230765.

It is an arithmetic number, because the mean of its divisors is an integer number (452545068690).

Almost surely, 2^{21731664311375} is an apocalyptic number.

21731664311375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21731664311375 is a deficient number, since it is larger than the sum of its proper divisors (7231220084785).

21731664311375 is a wasteful number, since it uses less digits than its factorization.

21731664311375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1233981 (or 1233971 counting only the distinct ones).

The product of its digits is 1905120, while the sum is 50.

The spelling of 21731664311375 in words is "twenty-one trillion, seven hundred thirty-one billion, six hundred sixty-four million, three hundred eleven thousand, three hundred seventy-five".