18187812 has 36 divisors (see below), whose sum is σ = 46759440. Its totient is φ = 5959152.

The previous prime is 18187789. The next prime is 18187837. The reversal of 18187812 is 21878181.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an alternating number because its digits alternate between odd and even.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2158 + ... + 6405.

Almost surely, 2^18187812 is an apocalyptic number.

18187812 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

18187812 is an abundant number, since it is smaller than the sum of its proper divisors (28571628).

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

18187812 is a wasteful number, since it uses less digits than its factorization.

18187812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8632 (or 8627 counting only the distinct ones).

The product of its digits is 7168, while the sum is 36.

The square root of 18187812 is about 4264.7171066789. The cubic root of 18187812 is about 262.9824813518.

The spelling of 18187812 in words is "eighteen million, one hundred eighty-seven thousand, eight hundred twelve".