165856138 has 48 divisors (see below), whose sum is σ = 301607424. Its totient is φ = 66935520.

The previous prime is 165856121. The next prime is 165856153. The reversal of 165856138 is 831658561.

165856138 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 165856094 and 165856103.

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 23 ways as a sum of consecutive naturals, for example, 958620 + ... + 958792.

It is an arithmetic number, because the mean of its divisors is an integer number (6283488).

Almost surely, 2^165856138 is an apocalyptic number.

165856138 is a deficient number, since it is larger than the sum of its proper divisors (135751286).

165856138 is a wasteful number, since it uses less digits than its factorization.

165856138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 307 (or 260 counting only the distinct ones).

The product of its digits is 172800, while the sum is 43.

The square root of 165856138 is about 12878.5145882590. The cubic root of 165856138 is about 549.4276558502.

The spelling of 165856138 in words is "one hundred sixty-five million, eight hundred fifty-six thousand, one hundred thirty-eight".