165905885 has 8 divisors (see below), whose sum is σ = 203943096. Its totient is φ = 129487360.

The previous prime is 165905881. The next prime is 165905899. The reversal of 165905885 is 588509561.

It can be written as a sum of positive squares in 4 ways, for example, as 63001 + 165842884 = 251^2 + 12878^2 .

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

It is not a de Polignac number, because 165905885 - 2² = 165905881 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 (165905881) 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, 404444 + ... + 404853.

It is an arithmetic number, because the mean of its divisors is an integer number (25492887).

Almost surely, 2^165905885 is an apocalyptic number.

It is an amenable number.

165905885 is a deficient number, since it is larger than the sum of its proper divisors (38037211).

165905885 is an equidigital number, since it uses as much as digits as its factorization.

165905885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 809343.

The product of its (nonzero) digits is 432000, while the sum is 47.

The square root of 165905885 is about 12880.4458385570. The cubic root of 165905885 is about 549.4825822575.

The spelling of 165905885 in words is "one hundred sixty-five million, nine hundred five thousand, eight hundred eighty-five".