165910889 has 4 divisors (see below), whose sum is σ = 166070100. Its totient is φ = 165751680.

The previous prime is 165910867. The next prime is 165910903. The reversal of 165910889 is 988019561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 988019561 = 449 ⋅2200489.

It can be written as a sum of positive squares in 2 ways, for example, as 113955625 + 51955264 = 10675^2 + 7208^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165910889 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (165910859) 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, 78032 + ... + 80129.

It is an arithmetic number, because the mean of its divisors is an integer number (41517525).

Almost surely, 2^165910889 is an apocalyptic number.

It is an amenable number.

165910889 is a deficient number, since it is larger than the sum of its proper divisors (159211).

165910889 is a wasteful number, since it uses less digits than its factorization.

165910889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159210.

The product of its (nonzero) digits is 155520, while the sum is 47.

The square root of 165910889 is about 12880.6400850268. The cubic root of 165910889 is about 549.4881066410.

The spelling of 165910889 in words is "one hundred sixty-five million, nine hundred ten thousand, eight hundred eighty-nine".