166405664 has 12 divisors (see below), whose sum is σ = 327611214. Its totient is φ = 83202816.

The previous prime is 166405633. The next prime is 166405669. The reversal of 166405664 is 466504661.

It can be written as a sum of positive squares in only one way, i.e., 132066064 + 34339600 = 11492^2 + 5860^2 .

It is a super-2 number, since 2×166405664² = 55381690022561792, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (166405669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2600057 + ... + 2600120.

Almost surely, 2^166405664 is an apocalyptic number.

It is an amenable number.

166405664 is a deficient number, since it is larger than the sum of its proper divisors (161205550).

166405664 is an equidigital number, since it uses as much as digits as its factorization.

166405664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5200187 (or 5200179 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 38.

The square root of 166405664 is about 12899.8319368897. The cubic root of 166405664 is about 550.0337874560.

The spelling of 166405664 in words is "one hundred sixty-six million, four hundred five thousand, six hundred sixty-four".