18664613 has 16 divisors (see below), whose sum is σ = 21140160. Its totient is φ = 16465680.

The previous prime is 18664579. The next prime is 18664627. The reversal of 18664613 is 31646681.

It is not a de Polignac number, because 18664613 - 2¹² = 18660517 is a prime.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18664673) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49058 + ... + 49436.

It is an arithmetic number, because the mean of its divisors is an integer number (1321260).

Almost surely, 2^18664613 is an apocalyptic number.

It is an amenable number.

18664613 is a deficient number, since it is larger than the sum of its proper divisors (2475547).

18664613 is an equidigital number, since it uses as much as digits as its factorization.

18664613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 449 (or 427 counting only the distinct ones).

The product of its digits is 20736, while the sum is 35.

The square root of 18664613 is about 4320.2561266666. The cubic root of 18664613 is about 265.2607520064.

The spelling of 18664613 in words is "eighteen million, six hundred sixty-four thousand, six hundred thirteen".