165997879 has 2 divisors, whose sum is σ = 165997880. Its totient is φ = 165997878.

The previous prime is 165997861. The next prime is 165997903. The reversal of 165997879 is 978799561.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 165997879 - 2⁷ = 165997751 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165997079) 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, 82998939 + 82998940.

It is an arithmetic number, because the mean of its divisors is an integer number (82998940).

Almost surely, 2^165997879 is an apocalyptic number.

165997879 is a deficient number, since it is larger than the sum of its proper divisors (1).

165997879 is an equidigital number, since it uses as much as digits as its factorization.

165997879 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8573040, while the sum is 61.

The square root of 165997879 is about 12884.0164156989. The cubic root of 165997879 is about 549.5841252909.

The spelling of 165997879 in words is "one hundred sixty-five million, nine hundred ninety-seven thousand, eight hundred seventy-nine".