18656638479 has 18 divisors (see below), whose sum is σ = 28441473216. Its totient is φ = 11783138040.

The previous prime is 18656638421. The next prime is 18656638523. The reversal of 18656638479 is 97483665681.

18656638479 is a `hidden beast` number, since 1 + 86 + 56 + 6 + 38 + 479 = 666.

It is not a de Polignac number, because 18656638479 - 2⁸ = 18656638223 is a prime.

It is a super-2 number, since 2×18656638479² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18656638379) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 2867887 + ... + 2874384.

Almost surely, 2^18656638479 is an apocalyptic number.

18656638479 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

18656638479 is a deficient number, since it is larger than the sum of its proper divisors (9784834737).

18656638479 is a wasteful number, since it uses less digits than its factorization.

18656638479 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5742315 (or 5742293 counting only the distinct ones).

The product of its digits is 52254720, while the sum is 63.

The spelling of 18656638479 in words is "eighteen billion, six hundred fifty-six million, six hundred thirty-eight thousand, four hundred seventy-nine".