18368991056 has 20 divisors (see below), whose sum is σ = 38327606772. Its totient is φ = 8477995776.

The previous prime is 18368991041. The next prime is 18368991071. The reversal of 18368991056 is 65019986381.

It is an interprime number because it is at equal distance from previous prime (18368991041) and next prime (18368991071).

It can be written as a sum of positive squares in 2 ways, for example, as 4108810000 + 14260181056 = 64100^2 + 119416^2 .

It is a junction number, because it is equal to n+sod(n) for n = 18368990992 and 18368991010.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44156021 + ... + 44156436.

Almost surely, 2^18368991056 is an apocalyptic number.

18368991056 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

18368991056 is an abundant number, since it is smaller than the sum of its proper divisors (19958615716).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18368991056 is a wasteful number, since it uses less digits than its factorization.

18368991056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88312478 (or 88312472 counting only the distinct ones).

The product of its (nonzero) digits is 2799360, while the sum is 56.

The spelling of 18368991056 in words is "eighteen billion, three hundred sixty-eight million, nine hundred ninety-one thousand, fifty-six".