165559399 has 2 divisors, whose sum is σ = 165559400. Its totient is φ = 165559398.

The previous prime is 165559367. The next prime is 165559409. The reversal of 165559399 is 993955561.

It is a strong prime.

It is an emirp because it is prime and its reverse (993955561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 165559399 - 2⁵ = 165559367 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165559319) 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, 82779699 + 82779700.

It is an arithmetic number, because the mean of its divisors is an integer number (82779700).

Almost surely, 2^165559399 is an apocalyptic number.

165559399 is a deficient number, since it is larger than the sum of its proper divisors (1).

165559399 is an equidigital number, since it uses as much as digits as its factorization.

165559399 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1640250, while the sum is 52.

The square root of 165559399 is about 12866.9887308570. The cubic root of 165559399 is about 549.0997935164.

The spelling of 165559399 in words is "one hundred sixty-five million, five hundred fifty-nine thousand, three hundred ninety-nine".