165998359 has 4 divisors (see below), whose sum is σ = 166425480. Its totient is φ = 165571240.

The previous prime is 165998351. The next prime is 165998431. The reversal of 165998359 is 953899561.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 165998359 - 2³ = 165998351 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165998351) 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 in 3 ways as a sum of consecutive naturals, for example, 212977 + ... + 213754.

It is an arithmetic number, because the mean of its divisors is an integer number (41606370).

Almost surely, 2^165998359 is an apocalyptic number.

165998359 is a deficient number, since it is larger than the sum of its proper divisors (427121).

165998359 is an equidigital number, since it uses as much as digits as its factorization.

165998359 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 427120.

The product of its digits is 2624400, while the sum is 55.

The square root of 165998359 is about 12884.0350434171. The cubic root of 165998359 is about 549.5846550168.

The spelling of 165998359 in words is "one hundred sixty-five million, nine hundred ninety-eight thousand, three hundred fifty-nine".