166616657 has 2 divisors, whose sum is σ = 166616658. Its totient is φ = 166616656.

The previous prime is 166616647. The next prime is 166616663. The reversal of 166616657 is 756616661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 147962896 + 18653761 = 12164^2 + 4319^2 .

It is a cyclic number.

It is not a de Polignac number, because 166616657 - 2¹⁰ = 166615633 is a prime.

It is a super-2 number, since 2×166616657² = 55522220779711298, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (166616617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83308328 + 83308329.

It is an arithmetic number, because the mean of its divisors is an integer number (83308329).

Almost surely, 2^166616657 is an apocalyptic number.

It is an amenable number.

166616657 is a deficient number, since it is larger than the sum of its proper divisors (1).

166616657 is an equidigital number, since it uses as much as digits as its factorization.

166616657 is an evil number, because the sum of its binary digits is even.

The product of its digits is 272160, while the sum is 44.

The square root of 166616657 is about 12908.0074759817. The cubic root of 166616657 is about 550.2661598825.

The spelling of 166616657 in words is "one hundred sixty-six million, six hundred sixteen thousand, six hundred fifty-seven".