165444817 has 2 divisors, whose sum is σ = 165444818. Its totient is φ = 165444816.

The previous prime is 165444809. The next prime is 165444821. The reversal of 165444817 is 718444561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 164891281 + 553536 = 12841^2 + 744^2 .

It is a cyclic number.

It is not a de Polignac number, because 165444817 - 2³ = 165444809 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 165444817.

It is not a weakly prime, because it can be changed into another prime (165444827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82722408 + 82722409.

It is an arithmetic number, because the mean of its divisors is an integer number (82722409).

Almost surely, 2^165444817 is an apocalyptic number.

It is an amenable number.

165444817 is a deficient number, since it is larger than the sum of its proper divisors (1).

165444817 is an equidigital number, since it uses as much as digits as its factorization.

165444817 is an evil number, because the sum of its binary digits is even.

The product of its digits is 107520, while the sum is 40.

The square root of 165444817 is about 12862.5354032555. The cubic root of 165444817 is about 548.9730887945.

The spelling of 165444817 in words is "one hundred sixty-five million, four hundred forty-four thousand, eight hundred seventeen".