18399888 has 60 divisors (see below), whose sum is σ = 55460860. Its totient is φ = 5660928.

The previous prime is 18399883. The next prime is 18399907. The reversal of 18399888 is 88899381.

It can be written as a sum of positive squares in 2 ways, for example, as 10036224 + 8363664 = 3168^2 + 2892^2 .

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (18399883) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3043 + ... + 6786.

Almost surely, 2^18399888 is an apocalyptic number.

18399888 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

18399888 is an abundant number, since it is smaller than the sum of its proper divisors (37060972).

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

18399888 is a wasteful number, since it uses less digits than its factorization.

18399888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9856 (or 9847 counting only the distinct ones).

The product of its digits is 995328, while the sum is 54.

The square root of 18399888 is about 4289.5090628183. The cubic root of 18399888 is about 264.0006887034. Note that the first 3 decimals are identical.

Adding to 18399888 its product of digits (995328), we get a square (19395216 = 4404²).

The spelling of 18399888 in words is "eighteen million, three hundred ninety-nine thousand, eight hundred eighty-eight".