165856775 has 12 divisors (see below), whose sum is σ = 235042992. Its totient is φ = 113730240.

The previous prime is 165856759. The next prime is 165856783. The reversal of 165856775 is 577658561.

It is a happy number.

It is not a de Polignac number, because 165856775 - 2⁴ = 165856759 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 473702 + ... + 474051.

It is an arithmetic number, because the mean of its divisors is an integer number (19586916).

Almost surely, 2^165856775 is an apocalyptic number.

165856775 is a deficient number, since it is larger than the sum of its proper divisors (69186217).

165856775 is an equidigital number, since it uses as much as digits as its factorization.

165856775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 947770 (or 947765 counting only the distinct ones).

The product of its digits is 1764000, while the sum is 50.

The square root of 165856775 is about 12878.5393193483. The cubic root of 165856775 is about 549.4283592409.

The spelling of 165856775 in words is "one hundred sixty-five million, eight hundred fifty-six thousand, seven hundred seventy-five".