166661931 has 16 divisors (see below), whose sum is σ = 237579264. Its totient is φ = 103553664.

The previous prime is 166661899. The next prime is 166661941. The reversal of 166661931 is 139166661.

It is not a de Polignac number, because 166661931 - 2⁵ = 166661899 is a prime.

It is a super-2 number, since 2×166661931² = 55552398489297522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 166661931.

It is not an unprimeable number, because it can be changed into a prime (166661941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10611 + ... + 21116.

It is an arithmetic number, because the mean of its divisors is an integer number (14848704).

Almost surely, 2^166661931 is an apocalyptic number.

166661931 is a deficient number, since it is larger than the sum of its proper divisors (70917333).

166661931 is a wasteful number, since it uses less digits than its factorization.

166661931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31850.

The product of its digits is 34992, while the sum is 39.

The square root of 166661931 is about 12909.7610744738. The cubic root of 166661931 is about 550.3159958241.

The spelling of 166661931 in words is "one hundred sixty-six million, six hundred sixty-one thousand, nine hundred thirty-one".