21479863923 has 24 divisors (see below), whose sum is σ = 35478463488. Its totient is φ = 12267409392.

The previous prime is 21479863913. The next prime is 21479863939. The reversal of 21479863923 is 32936897412.

21479863923 is a `hidden beast` number, since 2 + 1 + 479 + 86 + 3 + 92 + 3 = 666.

It is not a de Polignac number, because 21479863923 - 2⁸ = 21479863667 is a prime.

It is a super-2 number, since 2×21479863923² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21479863923.

It is not an unprimeable number, because it can be changed into a prime (21479863913) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21336 + ... + 208362.

It is an arithmetic number, because the mean of its divisors is an integer number (1478269312).

Almost surely, 2^21479863923 is an apocalyptic number.

21479863923 is a deficient number, since it is larger than the sum of its proper divisors (13998599565).

21479863923 is a wasteful number, since it uses less digits than its factorization.

21479863923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188863 (or 188860 counting only the distinct ones).

The product of its digits is 3919104, while the sum is 54.

The spelling of 21479863923 in words is "twenty-one billion, four hundred seventy-nine million, eight hundred sixty-three thousand, nine hundred twenty-three".