18664247 has 12 divisors (see below), whose sum is σ = 22656816. Its totient is φ = 15301440.

The previous prime is 18664229. The next prime is 18664253. The reversal of 18664247 is 74246681.

It is not a de Polignac number, because 18664247 - 2⁶ = 18664183 is a prime.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 18664247.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18664297) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7154 + ... + 9407.

It is an arithmetic number, because the mean of its divisors is an integer number (1888068).

Almost surely, 2^18664247 is an apocalyptic number.

18664247 is a deficient number, since it is larger than the sum of its proper divisors (3992569).

18664247 is a wasteful number, since it uses less digits than its factorization.

18664247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16598 (or 16591 counting only the distinct ones).

The product of its digits is 64512, while the sum is 38.

The square root of 18664247 is about 4320.2137678592. The cubic root of 18664247 is about 265.2590181358.

The spelling of 18664247 in words is "eighteen million, six hundred sixty-four thousand, two hundred forty-seven".