18664 has 8 divisors (see below), whose sum is σ = 35010. Its totient is φ = 9328.

The previous prime is 18661. The next prime is 18671. The reversal of 18664 is 46681.

It can be written as a sum of positive squares in only one way, i.e., 16900 + 1764 = 130^2 + 42^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a plaindrome in base 6.

It is a nialpdrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (18661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1159 + ... + 1174.

2¹⁸⁶⁶⁴ is an apocalyptic number.

It is an amenable number.

18664 is a deficient number, since it is larger than the sum of its proper divisors (16346).

18664 is a wasteful number, since it uses less digits than its factorization.

18664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2339 (or 2335 counting only the distinct ones).

The product of its digits is 1152, while the sum is 25.

The square root of 18664 is about 136.6162508635. The cubic root of 18664 is about 26.5257847997.

The spelling of 18664 in words is "eighteen thousand, six hundred sixty-four".