18664256 has 28 divisors (see below), whose sum is σ = 39887652. Its totient is φ = 8613888.

The previous prime is 18664253. The next prime is 18664259. The reversal of 18664256 is 65246681.

It is an interprime number because it is at equal distance from previous prime (18664253) and next prime (18664259).

It can be written as a sum of positive squares in 2 ways, for example, as 10137856 + 8526400 = 3184^2 + 2920^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18664253) 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, 10385 + ... + 12048.

It is an arithmetic number, because the mean of its divisors is an integer number (1424559).

Almost surely, 2^18664256 is an apocalyptic number.

18664256 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

18664256 is an abundant number, since it is smaller than the sum of its proper divisors (21223396).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18664256 is a wasteful number, since it uses less digits than its factorization.

18664256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22458 (or 22448 counting only the distinct ones).

The product of its digits is 69120, while the sum is 38.

The square root of 18664256 is about 4320.2148094742. The cubic root of 18664256 is about 265.2590607722.

The spelling of 18664256 in words is "eighteen million, six hundred sixty-four thousand, two hundred fifty-six".