18381800 has 24 divisors (see below), whose sum is σ = 42738150. Its totient is φ = 7352640.

The previous prime is 18381787. The next prime is 18381821. The reversal of 18381800 is 818381.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 17825284 + 556516 = 4222^2 + 746^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 45755 + ... + 46154.

Almost surely, 2^18381800 is an apocalyptic number.

18381800 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18381800 is an abundant number, since it is smaller than the sum of its proper divisors (24356350).

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

18381800 is a wasteful number, since it uses less digits than its factorization.

18381800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91925 (or 91916 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 29.

The square root of 18381800 is about 4287.4001446098. The cubic root of 18381800 is about 263.9141517622.

The spelling of 18381800 in words is "eighteen million, three hundred eighty-one thousand, eight hundred".