18131630 has 32 divisors (see below), whose sum is σ = 35831808. Its totient is φ = 6551200.

The previous prime is 18131623. The next prime is 18131647. The reversal of 18131630 is 3613181.

It is a plaindrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 18131596 and 18131605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20579 + ... + 21441.

It is an arithmetic number, because the mean of its divisors is an integer number (1119744).

Almost surely, 2^18131630 is an apocalyptic number.

18131630 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18131630 is a deficient number, since it is larger than the sum of its proper divisors (17700178).

18131630 is a wasteful number, since it uses less digits than its factorization.

18131630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1072.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 18131630 is about 4258.1251742991. The cubic root of 18131630 is about 262.7114184903.

It can be divided in two parts, 1813 and 1630, that added together give a palindrome (3443).

The spelling of 18131630 in words is "eighteen million, one hundred thirty-one thousand, six hundred thirty".