16664 has 8 divisors (see below), whose sum is σ = 31260. Its totient is φ = 8328.

The previous prime is 16661. The next prime is 16673. The reversal of 16664 is 46661.

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

It is a super-4 number, since 4×16664⁴ = 308444491846795264, which contains 4444 as substring.

It is a plaindrome in base 11 and base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1034 + ... + 1049.

2¹⁶⁶⁶⁴ is an apocalyptic number.

It is an amenable number.

16664 is a deficient number, since it is larger than the sum of its proper divisors (14596).

16664 is a wasteful number, since it uses less digits than its factorization.

16664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2089 (or 2085 counting only the distinct ones).

The product of its digits is 864, while the sum is 23.

The square root of 16664 is about 129.0891165048. The cubic root of 16664 is about 25.5422853459.

Subtracting from 16664 its sum of digits (23), we obtain a square (16641 = 129²).

The spelling of 16664 in words is "sixteen thousand, six hundred sixty-four".