165117391 has 8 divisors (see below), whose sum is σ = 181365120. Its totient is φ = 149625432.

The previous prime is 165117389. The next prime is 165117397. The reversal of 165117391 is 193711561.

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

It is a cyclic number.

It is not a de Polignac number, because 165117391 - 2¹ = 165117389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165117397) 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, 188485 + ... + 189358.

It is an arithmetic number, because the mean of its divisors is an integer number (22670640).

Almost surely, 2^165117391 is an apocalyptic number.

165117391 is a deficient number, since it is larger than the sum of its proper divisors (16247729).

165117391 is a wasteful number, since it uses less digits than its factorization.

165117391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 377885.

The product of its digits is 5670, while the sum is 34.

The square root of 165117391 is about 12849.8012046880. The cubic root of 165117391 is about 548.6106985344.

The spelling of 165117391 in words is "one hundred sixty-five million, one hundred seventeen thousand, three hundred ninety-one".