165961657 has 2 divisors, whose sum is σ = 165961658. Its totient is φ = 165961656.

The previous prime is 165961651. The next prime is 165961669. The reversal of 165961657 is 756169561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 163942416 + 2019241 = 12804^2 + 1421^2 .

It is a cyclic number.

It is not a de Polignac number, because 165961657 - 2¹⁹ = 165437369 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (165961651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82980828 + 82980829.

It is an arithmetic number, because the mean of its divisors is an integer number (82980829).

Almost surely, 2^165961657 is an apocalyptic number.

It is an amenable number.

165961657 is a deficient number, since it is larger than the sum of its proper divisors (1).

165961657 is an equidigital number, since it uses as much as digits as its factorization.

165961657 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 340200, while the sum is 46.

The square root of 165961657 is about 12882.6106438097. The cubic root of 165961657 is about 549.5441479040.

The spelling of 165961657 in words is "one hundred sixty-five million, nine hundred sixty-one thousand, six hundred fifty-seven".