18131636 has 12 divisors (see below), whose sum is σ = 33110112. Its totient is φ = 8671608.

The previous prime is 18131623. The next prime is 18131647. The reversal of 18131636 is 63613181.

It is a junction number, because it is equal to n+sod(n) for n = 18131599 and 18131608.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 98450 + ... + 98633.

It is an arithmetic number, because the mean of its divisors is an integer number (2759176).

Almost surely, 2^18131636 is an apocalyptic number.

It is an amenable number.

18131636 is a deficient number, since it is larger than the sum of its proper divisors (14978476).

18131636 is a wasteful number, since it uses less digits than its factorization.

18131636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197110 (or 197108 counting only the distinct ones).

The product of its digits is 2592, while the sum is 29.

The square root of 18131636 is about 4258.1258788345. The cubic root of 18131636 is about 262.7114474686.

The spelling of 18131636 in words is "eighteen million, one hundred thirty-one thousand, six hundred thirty-six".