21916663475 has 12 divisors (see below), whose sum is σ = 31059043344. Its totient is φ = 15028569120.

The previous prime is 21916663451. The next prime is 21916663501. The reversal of 21916663475 is 57436661912.

It is not a de Polignac number, because 21916663475 - 2¹⁶ = 21916597939 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 62618864 + ... + 62619213.

It is an arithmetic number, because the mean of its divisors is an integer number (2588253612).

Almost surely, 2^21916663475 is an apocalyptic number.

21916663475 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21916663475 is a deficient number, since it is larger than the sum of its proper divisors (9142379869).

21916663475 is a wasteful number, since it uses less digits than its factorization.

21916663475 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125238094 (or 125238089 counting only the distinct ones).

The product of its digits is 1632960, while the sum is 50.

It can be divided in two parts, 2191 and 6663475, that added together give a palindrome (6665666).

The spelling of 21916663475 in words is "twenty-one billion, nine hundred sixteen million, six hundred sixty-three thousand, four hundred seventy-five".