18789915640 has 16 divisors (see below), whose sum is σ = 42277310280. Its totient is φ = 7515966240.

The previous prime is 18789915637. The next prime is 18789915667. The reversal of 18789915640 is 4651998781.

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, 234873906 + ... + 234873985.

Almost surely, 2^18789915640 is an apocalyptic number.

18789915640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18789915640 is an abundant number, since it is smaller than the sum of its proper divisors (23487394640).

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

18789915640 is a wasteful number, since it uses less digits than its factorization.

18789915640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 469747902 (or 469747898 counting only the distinct ones).

The product of its (nonzero) digits is 4354560, while the sum is 58.

The spelling of 18789915640 in words is "eighteen billion, seven hundred eighty-nine million, nine hundred fifteen thousand, six hundred forty".