166672666 has 4 divisors (see below), whose sum is σ = 250009002. Its totient is φ = 83336332.

The previous prime is 166672631. The next prime is 166672711. The reversal of 166672666 is 666276661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 666276661 = 5827 ⋅114343.

It can be written as a sum of positive squares in only one way, i.e., 165662641 + 1010025 = 12871^2 + 1005^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41668165 + ... + 41668168.

Almost surely, 2^166672666 is an apocalyptic number.

166672666 is a deficient number, since it is larger than the sum of its proper divisors (83336336).

166672666 is an equidigital number, since it uses as much as digits as its factorization.

166672666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83336335.

The product of its digits is 653184, while the sum is 46.

The square root of 166672666 is about 12910.1768384480. The cubic root of 166672666 is about 550.3278111906.

The spelling of 166672666 in words is "one hundred sixty-six million, six hundred seventy-two thousand, six hundred sixty-six".