21311993375 has 16 divisors (see below), whose sum is σ = 26841397440. Its totient is φ = 16893165600.

The previous prime is 21311993369. The next prime is 21311993383. The reversal of 21311993375 is 57339911312.

It is not a de Polignac number, because 21311993375 - 2²⁰ = 21310944799 is a prime.

It is a congruent number.

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, 768467 + ... + 795716.

It is an arithmetic number, because the mean of its divisors is an integer number (1677587340).

Almost surely, 2^21311993375 is an apocalyptic number.

21311993375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21311993375 is a deficient number, since it is larger than the sum of its proper divisors (5529404065).

21311993375 is a wasteful number, since it uses less digits than its factorization.

21311993375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1564307 (or 1564297 counting only the distinct ones).

The product of its digits is 153090, while the sum is 44.

The spelling of 21311993375 in words is "twenty-one billion, three hundred eleven million, nine hundred ninety-three thousand, three hundred seventy-five".