165399 has 8 divisors (see below), whose sum is σ = 237552. Its totient is φ = 101760.

The previous prime is 165397. The next prime is 165437. The reversal of 165399 is 993561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 165399 - 2¹ = 165397 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165391) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2082 + ... + 2159.

It is an arithmetic number, because the mean of its divisors is an integer number (29694).

2¹⁶⁵³⁹⁹ is an apocalyptic number.

165399 is a deficient number, since it is larger than the sum of its proper divisors (72153).

165399 is a wasteful number, since it uses less digits than its factorization.

165399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4257.

The product of its digits is 7290, while the sum is 33.

The square root of 165399 is about 406.6927587258. The cubic root of 165399 is about 54.8922408004.

The spelling of 165399 in words is "one hundred sixty-five thousand, three hundred ninety-nine".