165158881 has 4 divisors (see below), whose sum is σ = 165238164. Its totient is φ = 165079600.

The previous prime is 165158869. The next prime is 165158891. The reversal of 165158881 is 188851561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 188851561 = 53 ⋅3563237.

It can be written as a sum of positive squares in 2 ways, for example, as 118701025 + 46457856 = 10895^2 + 6816^2 .

It is a cyclic number.

It is not a de Polignac number, because 165158881 - 2⁹ = 165158369 is a prime.

It is a super-3 number, since 3×165158881³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165158821) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36430 + ... + 40711.

It is an arithmetic number, because the mean of its divisors is an integer number (41309541).

Almost surely, 2^165158881 is an apocalyptic number.

It is an amenable number.

165158881 is a deficient number, since it is larger than the sum of its proper divisors (79283).

165158881 is an equidigital number, since it uses as much as digits as its factorization.

165158881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79282.

The product of its digits is 76800, while the sum is 43.

The square root of 165158881 is about 12851.4155251474. The cubic root of 165158881 is about 548.6566455452.

The spelling of 165158881 in words is "one hundred sixty-five million, one hundred fifty-eight thousand, eight hundred eighty-one".