18637313 has 4 divisors (see below), whose sum is σ = 18756180. Its totient is φ = 18518448.

The previous prime is 18637303. The next prime is 18637319. The reversal of 18637313 is 31373681.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4739329 + 13897984 = 2177^2 + 3728^2 .

It is a cyclic number.

It is not a de Polignac number, because 18637313 - 2⁸ = 18637057 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18637313.

It is not an unprimeable number, because it can be changed into a prime (18637319) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 59198 + ... + 59511.

It is an arithmetic number, because the mean of its divisors is an integer number (4689045).

Almost surely, 2^18637313 is an apocalyptic number.

It is an amenable number.

18637313 is a deficient number, since it is larger than the sum of its proper divisors (118867).

18637313 is a wasteful number, since it uses less digits than its factorization.

18637313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118866.

The product of its digits is 9072, while the sum is 32.

The square root of 18637313 is about 4317.0954355909. The cubic root of 18637313 is about 265.1313600552.

The spelling of 18637313 in words is "eighteen million, six hundred thirty-seven thousand, three hundred thirteen".