166680681 has 16 divisors (see below), whose sum is σ = 226361856. Its totient is φ = 109074816.

The previous prime is 166680649. The next prime is 166680727. The reversal of 166680681 is 186086661.

It is not a de Polignac number, because 166680681 - 2⁵ = 166680649 is a prime.

It is a super-2 number, since 2×166680681² = 55564898837247522, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (166680181) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47131 + ... + 50543.

It is an arithmetic number, because the mean of its divisors is an integer number (14147616).

Almost surely, 2^166680681 is an apocalyptic number.

It is an amenable number.

166680681 is a deficient number, since it is larger than the sum of its proper divisors (59681175).

166680681 is a wasteful number, since it uses less digits than its factorization.

166680681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3712.

The product of its (nonzero) digits is 82944, while the sum is 42.

The square root of 166680681 is about 12910.4872487447. The cubic root of 166680681 is about 550.3366324865.

The spelling of 166680681 in words is "one hundred sixty-six million, six hundred eighty thousand, six hundred eighty-one".