18131600 has 30 divisors (see below), whose sum is σ = 43562130. Its totient is φ = 7252480.

The previous prime is 18131593. The next prime is 18131609. The reversal of 18131600 is 613181.

It can be written as a sum of positive squares in 3 ways, for example, as 1517824 + 16613776 = 1232^2 + 4076^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (18131609) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 22265 + ... + 23064.

It is an arithmetic number, because the mean of its divisors is an integer number (1452071).

Almost surely, 2^18131600 is an apocalyptic number.

18131600 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18131600 is an abundant number, since it is smaller than the sum of its proper divisors (25430530).

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

18131600 is a wasteful number, since it uses less digits than its factorization.

18131600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45347 (or 45336 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 18131600 is about 4258.1216516206. The cubic root of 18131600 is about 262.7112735990.

Adding to 18131600 its reverse (613181), we get a palindrome (18744781).

The spelling of 18131600 in words is "eighteen million, one hundred thirty-one thousand, six hundred".