165115581 has 8 divisors (see below), whose sum is σ = 221032224. Its totient is φ = 109638000.

The previous prime is 165115547. The next prime is 165115583. The reversal of 165115581 is 185511561.

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

It is not a de Polignac number, because 165115581 - 2¹⁴ = 165099197 is a prime.

It is a super-2 number, since 2×165115581² = 54526310177935122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165115583) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 108886 + ... + 110391.

It is an arithmetic number, because the mean of its divisors is an integer number (27629028).

Almost surely, 2^165115581 is an apocalyptic number.

It is an amenable number.

165115581 is a deficient number, since it is larger than the sum of its proper divisors (55916643).

165115581 is a wasteful number, since it uses less digits than its factorization.

165115581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 219531.

The product of its digits is 6000, while the sum is 33.

The square root of 165115581 is about 12849.7307753898. The cubic root of 165115581 is about 548.6086939222.

The spelling of 165115581 in words is "one hundred sixty-five million, one hundred fifteen thousand, five hundred eighty-one".