18399790 has 32 divisors (see below), whose sum is σ = 35212320. Its totient is φ = 6902784.

The previous prime is 18399781. The next prime is 18399791. The reversal of 18399790 is 9799381.

It is a self number, because there is not a number n which added to its sum of digits gives 18399790.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18399791) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21042 + ... + 21898.

It is an arithmetic number, because the mean of its divisors is an integer number (1100385).

Almost surely, 2^18399790 is an apocalyptic number.

18399790 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18399790 is a deficient number, since it is larger than the sum of its proper divisors (16812530).

18399790 is a wasteful number, since it uses less digits than its factorization.

18399790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 996.

The product of its (nonzero) digits is 122472, while the sum is 46.

The square root of 18399790 is about 4289.4976395844. The cubic root of 18399790 is about 264.0002200029. Note that the first 3 decimals are identical.

Subtracting from 18399790 its sum of digits (46), we obtain a cube (18399744 = 264³).

The spelling of 18399790 in words is "eighteen million, three hundred ninety-nine thousand, seven hundred ninety".