165958999 has 2 divisors, whose sum is σ = 165959000. Its totient is φ = 165958998.

The previous prime is 165958997. The next prime is 165959011. The reversal of 165958999 is 999859561.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 165958999 - 2¹ = 165958997 is a prime.

Together with 165958997, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165958993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82979499 + 82979500.

It is an arithmetic number, because the mean of its divisors is an integer number (82979500).

Almost surely, 2^165958999 is an apocalyptic number.

165958999 is a deficient number, since it is larger than the sum of its proper divisors (1).

165958999 is an equidigital number, since it uses as much as digits as its factorization.

165958999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7873200, while the sum is 61.

The square root of 165958999 is about 12882.5074810768. The cubic root of 165958999 is about 549.5412141015.

The spelling of 165958999 in words is "one hundred sixty-five million, nine hundred fifty-eight thousand, nine hundred ninety-nine".