166441661 has 2 divisors, whose sum is σ = 166441662. Its totient is φ = 166441660.

The previous prime is 166441633. The next prime is 166441669. The reversal of 166441661 is 166144661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 138415225 + 28026436 = 11765^2 + 5294^2 .

It is a cyclic number.

It is not a de Polignac number, because 166441661 - 2²² = 162247357 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166441669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83220830 + 83220831.

It is an arithmetic number, because the mean of its divisors is an integer number (83220831).

Almost surely, 2^166441661 is an apocalyptic number.

It is an amenable number.

166441661 is a deficient number, since it is larger than the sum of its proper divisors (1).

166441661 is an equidigital number, since it uses as much as digits as its factorization.

166441661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 35.

The square root of 166441661 is about 12901.2271121781. The cubic root of 166441661 is about 550.0734458391.

The spelling of 166441661 in words is "one hundred sixty-six million, four hundred forty-one thousand, six hundred sixty-one".