18138996 has 72 divisors (see below), whose sum is σ = 50406720. Its totient is φ = 5474304.

The previous prime is 18138971. The next prime is 18138997. The reversal of 18138996 is 69983181.

18138996 is a `hidden beast` number, since 181 + 389 + 96 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18138997) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15156 + ... + 16308.

Almost surely, 2^18138996 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18138996, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25203360).

18138996 is an abundant number, since it is smaller than the sum of its proper divisors (32267724).

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

18138996 is a wasteful number, since it uses less digits than its factorization.

18138996 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1205 (or 1200 counting only the distinct ones).

The product of its digits is 93312, while the sum is 45.

The square root of 18138996 is about 4258.9900211200. The cubic root of 18138996 is about 262.7469893007.

The spelling of 18138996 in words is "eighteen million, one hundred thirty-eight thousand, nine hundred ninety-six".