18913933988 has 24 divisors (see below), whose sum is σ = 34649596800. Its totient is φ = 9016694720.

The previous prime is 18913933979. The next prime is 18913933999. The reversal of 18913933988 is 88933931981.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 18913933988.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 301913 + ... + 359136.

It is an arithmetic number, because the mean of its divisors is an integer number (1443733200).

Almost surely, 2^18913933988 is an apocalyptic number.

It is an amenable number.

18913933988 is a deficient number, since it is larger than the sum of its proper divisors (15735662812).

18913933988 is a wasteful number, since it uses less digits than its factorization.

18913933988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 661387 (or 661385 counting only the distinct ones).

The product of its digits is 10077696, while the sum is 62.

The spelling of 18913933988 in words is "eighteen billion, nine hundred thirteen million, nine hundred thirty-three thousand, nine hundred eighty-eight".