18666913 has 4 divisors (see below), whose sum is σ = 18679600. Its totient is φ = 18654228.

The previous prime is 18666889. The next prime is 18666917. The reversal of 18666913 is 31966681.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18666913 - 2⁵ = 18666881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18666917) 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, 3795 + ... + 7192.

It is an arithmetic number, because the mean of its divisors is an integer number (4669900).

Almost surely, 2^18666913 is an apocalyptic number.

It is an amenable number.

18666913 is a deficient number, since it is larger than the sum of its proper divisors (12687).

18666913 is a wasteful number, since it uses less digits than its factorization.

18666913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12686.

The product of its digits is 46656, while the sum is 40.

The square root of 18666913 is about 4320.5223063884. The cubic root of 18666913 is about 265.2716473956.

The spelling of 18666913 in words is "eighteen million, six hundred sixty-six thousand, nine hundred thirteen".