18131900 has 36 divisors (see below), whose sum is σ = 40622400. Its totient is φ = 7017600.

The previous prime is 18131879. The next prime is 18131921. The reversal of 18131900 is 913181.

It is an interprime number because it is at equal distance from previous prime (18131879) and next prime (18131921).

It is a super-2 number, since 2×18131900² = 657531595220000, which contains 22 as substring.

It is a plaindrome in base 16.

It is a congruent number.

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 11 ways as a sum of consecutive naturals, for example, 176 + ... + 6024.

It is an arithmetic number, because the mean of its divisors is an integer number (1128400).

Almost surely, 2^18131900 is an apocalyptic number.

18131900 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 18131900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20311200).

18131900 is an abundant number, since it is smaller than the sum of its proper divisors (22490500).

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

18131900 is a wasteful number, since it uses less digits than its factorization.

18131900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5894 (or 5887 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 23.

The square root of 18131900 is about 4258.1568782749. The cubic root of 18131900 is about 262.7127225049.

The spelling of 18131900 in words is "eighteen million, one hundred thirty-one thousand, nine hundred".