18638400 has 168 divisors, whose sum is σ = 66897504. Its totient is φ = 4505600.

The previous prime is 18638381. The next prime is 18638413. The reversal of 18638400 is 483681.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 52624 + ... + 52976.

Almost surely, 2^18638400 is an apocalyptic number.

18638400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18638400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33448752).

18638400 is an abundant number, since it is smaller than the sum of its proper divisors (48259104).

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

18638400 is a wasteful number, since it uses less digits than its factorization.

18638400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 389 (or 374 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 18638400 is about 4317.2213285862. The cubic root of 18638400 is about 265.1365144497.

The spelling of 18638400 in words is "eighteen million, six hundred thirty-eight thousand, four hundred".