165665879 has 2 divisors, whose sum is σ = 165665880. Its totient is φ = 165665878.

The previous prime is 165665779. The next prime is 165665911. The reversal of 165665879 is 978566561.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 165665879 - 2⁸ = 165665623 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 165665879.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165665179) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82832939 + 82832940.

It is an arithmetic number, because the mean of its divisors is an integer number (82832940).

Almost surely, 2^165665879 is an apocalyptic number.

165665879 is a deficient number, since it is larger than the sum of its proper divisors (1).

165665879 is an equidigital number, since it uses as much as digits as its factorization.

165665879 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2721600, while the sum is 53.

The square root of 165665879 is about 12871.1257860375. The cubic root of 165665879 is about 549.2174866550.

The spelling of 165665879 in words is "one hundred sixty-five million, six hundred sixty-five thousand, eight hundred seventy-nine".