18320780 has 24 divisors (see below), whose sum is σ = 38624208. Its totient is φ = 7299648.

The previous prime is 18320777. The next prime is 18320791. The reversal of 18320780 is 8702381.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3887 + ... + 7193.

It is an arithmetic number, because the mean of its divisors is an integer number (1609342).

Almost surely, 2^18320780 is an apocalyptic number.

18320780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18320780 is an abundant number, since it is smaller than the sum of its proper divisors (20303428).

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

18320780 is a wasteful number, since it uses less digits than its factorization.

18320780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3593 (or 3591 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 18320780 is about 4280.2780283528. The cubic root of 18320780 is about 263.6217992891.

The spelling of 18320780 in words is "eighteen million, three hundred twenty thousand, seven hundred eighty".