166315661 has 2 divisors, whose sum is σ = 166315662. Its totient is φ = 166315660.

The previous prime is 166315577. The next prime is 166315697. The reversal of 166315661 is 166513661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 112572100 + 53743561 = 10610^2 + 7331^2 .

It is a cyclic number.

It is not a de Polignac number, because 166315661 - 2¹⁰ = 166314637 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166315861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83157830 + 83157831.

It is an arithmetic number, because the mean of its divisors is an integer number (83157831).

Almost surely, 2^166315661 is an apocalyptic number.

It is an amenable number.

166315661 is a deficient number, since it is larger than the sum of its proper divisors (1).

166315661 is an equidigital number, since it uses as much as digits as its factorization.

166315661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19440, while the sum is 35.

The square root of 166315661 is about 12896.3429312344. The cubic root of 166315661 is about 549.9346048970.

The spelling of 166315661 in words is "one hundred sixty-six million, three hundred fifteen thousand, six hundred sixty-one".