18399936 has 56 divisors (see below), whose sum is σ = 49743360. Its totient is φ = 5999872.

The previous prime is 18399919. The next prime is 18399937. The reversal of 18399936 is 63999381.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (18399937) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8005 + ... + 10043.

Almost surely, 2^18399936 is an apocalyptic number.

18399936 is a gapful number since it is divisible by the number (16) 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 18399936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24871680).

18399936 is an abundant number, since it is smaller than the sum of its proper divisors (31343424).

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

18399936 is a wasteful number, since it uses less digits than its factorization.

18399936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2101 (or 2091 counting only the distinct ones).

The product of its digits is 314928, while the sum is 48.

The square root of 18399936 is about 4289.5146578605. The cubic root of 18399936 is about 264.0009182705. Note that the first 3 decimals are identical.

The spelling of 18399936 in words is "eighteen million, three hundred ninety-nine thousand, nine hundred thirty-six".