166665979 has 8 divisors (see below), whose sum is σ = 170891072. Its totient is φ = 162456840.

The previous prime is 166665959. The next prime is 166666001. The reversal of 166665979 is 979566661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 166665979 - 2¹⁹ = 166141691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166665959) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18784 + ... + 26194.

It is an arithmetic number, because the mean of its divisors is an integer number (21361384).

Almost surely, 2^166665979 is an apocalyptic number.

166665979 is a deficient number, since it is larger than the sum of its proper divisors (4225093).

166665979 is an equidigital number, since it uses as much as digits as its factorization.

166665979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7977.

The product of its digits is 3674160, while the sum is 55.

The square root of 166665979 is about 12909.9178541151. The cubic root of 166665979 is about 550.3204512730.

The spelling of 166665979 in words is "one hundred sixty-six million, six hundred sixty-five thousand, nine hundred seventy-nine".