166217992 has 8 divisors (see below), whose sum is σ = 311658750. Its totient is φ = 83108992.

The previous prime is 166217951. The next prime is 166218011. The reversal of 166217992 is 299712661.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 97891236 + 68326756 = 9894^2 + 8266^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10388617 + ... + 10388632.

Almost surely, 2^166217992 is an apocalyptic number.

It is an amenable number.

166217992 is a deficient number, since it is larger than the sum of its proper divisors (145440758).

166217992 is a wasteful number, since it uses less digits than its factorization.

166217992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20777255 (or 20777251 counting only the distinct ones).

The product of its digits is 81648, while the sum is 43.

The square root of 166217992 is about 12892.5556814776. Note that the first 3 decimals coincide. The cubic root of 166217992 is about 549.8269339776.

The spelling of 166217992 in words is "one hundred sixty-six million, two hundred seventeen thousand, nine hundred ninety-two".