18399400 has 24 divisors (see below), whose sum is σ = 42779070. Its totient is φ = 7359680.

The previous prime is 18399377. The next prime is 18399413. The reversal of 18399400 is 499381.

It can be written as a sum of positive squares in 3 ways, for example, as 14455204 + 3944196 = 3802^2 + 1986^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 45799 + ... + 46198.

Almost surely, 2^18399400 is an apocalyptic number.

18399400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18399400 is an abundant number, since it is smaller than the sum of its proper divisors (24379670).

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

18399400 is a wasteful number, since it uses less digits than its factorization.

18399400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92013 (or 92004 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 18399400 is about 4289.4521794747. The cubic root of 18399400 is about 263.9983547495.

The spelling of 18399400 in words is "eighteen million, three hundred ninety-nine thousand, four hundred".