18686685540 has 24 divisors (see below), whose sum is σ = 52322719680. Its totient is φ = 4983116128.

The previous prime is 18686685539. The next prime is 18686685541. The reversal of 18686685540 is 4558668681.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18686685539) and next prime (18686685541).

It is not an unprimeable number, because it can be changed into a prime (18686685541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 155722320 + ... + 155722439.

It is an arithmetic number, because the mean of its divisors is an integer number (2180113320).

Almost surely, 2^18686685540 is an apocalyptic number.

18686685540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18686685540 is an abundant number, since it is smaller than the sum of its proper divisors (33636034140).

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

18686685540 is a wasteful number, since it uses less digits than its factorization.

18686685540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 311444771 (or 311444769 counting only the distinct ones).

The product of its (nonzero) digits is 11059200, while the sum is 57.

The spelling of 18686685540 in words is "eighteen billion, six hundred eighty-six million, six hundred eighty-five thousand, five hundred forty".