166171661 has 2 divisors, whose sum is σ = 166171662. Its totient is φ = 166171660.

The previous prime is 166171637. The next prime is 166171679.

166171661 is nontrivially palindromic in base 10.

166171661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 160909225 + 5262436 = 12685^2 + 2294^2 .

It is a palprime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166171661 is a prime.

It is a super-3 number, since 3×166171661³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166171261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83085830 + 83085831.

It is an arithmetic number, because the mean of its divisors is an integer number (83085831).

Almost surely, 2^166171661 is an apocalyptic number.

It is an amenable number.

166171661 is a deficient number, since it is larger than the sum of its proper divisors (1).

166171661 is an equidigital number, since it uses as much as digits as its factorization.

166171661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9072, while the sum is 35.

The square root of 166171661 is about 12890.7587441547. The cubic root of 166171661 is about 549.7758436421.

The spelling of 166171661 in words is "one hundred sixty-six million, one hundred seventy-one thousand, six hundred sixty-one".