165981317 has 8 divisors (see below), whose sum is σ = 173471424. Its totient is φ = 158514048.

The previous prime is 165981301. The next prime is 165981329. The reversal of 165981317 is 713189561.

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 165981317 - 2⁴ = 165981301 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 (165981367) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10118 + ... + 20840.

It is an arithmetic number, because the mean of its divisors is an integer number (21683928).

Almost surely, 2^165981317 is an apocalyptic number.

It is an amenable number.

165981317 is a deficient number, since it is larger than the sum of its proper divisors (7490107).

165981317 is a wasteful number, since it uses less digits than its factorization.

165981317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11419.

The product of its digits is 45360, while the sum is 41.

The square root of 165981317 is about 12883.3736653099. The cubic root of 165981317 is about 549.5658469148.

The spelling of 165981317 in words is "one hundred sixty-five million, nine hundred eighty-one thousand, three hundred seventeen".