19998564836 has 48 divisors (see below), whose sum is σ = 38829067200. Its totient is φ = 8973724032.

The previous prime is 19998564827. The next prime is 19998564847. The reversal of 19998564836 is 63846589991.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31211 + ... + 202413.

It is an arithmetic number, because the mean of its divisors is an integer number (808938900).

Almost surely, 2^19998564836 is an apocalyptic number.

It is an amenable number.

19998564836 is a deficient number, since it is larger than the sum of its proper divisors (18830502364).

19998564836 is a wasteful number, since it uses less digits than its factorization.

19998564836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171308 (or 171306 counting only the distinct ones).

The product of its digits is 100776960, while the sum is 68.

The spelling of 19998564836 in words is "nineteen billion, nine hundred ninety-eight million, five hundred sixty-four thousand, eight hundred thirty-six".