18044563894 has 64 divisors (see below), whose sum is σ = 32209344000. Its totient is φ = 7576408224.

The previous prime is 18044563871. The next prime is 18044563913. The reversal of 18044563894 is 49836544081.

It is a super-2 number, since 2×18044563894² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16067617 + ... + 16068739.

It is an arithmetic number, because the mean of its divisors is an integer number (503271000).

Almost surely, 2^18044563894 is an apocalyptic number.

18044563894 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

18044563894 is a deficient number, since it is larger than the sum of its proper divisors (14164780106).

18044563894 is a wasteful number, since it uses less digits than its factorization.

18044563894 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1602 (or 1588 counting only the distinct ones).

The product of its (nonzero) digits is 3317760, while the sum is 52.

The spelling of 18044563894 in words is "eighteen billion, forty-four million, five hundred sixty-three thousand, eight hundred ninety-four".