165856737 has 4 divisors (see below), whose sum is σ = 221142320. Its totient is φ = 110571156.

The previous prime is 165856699. The next prime is 165856759. The reversal of 165856737 is 737658561.

165856737 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 165856737 - 2¹⁹ = 165332449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165856337) 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, 27642787 + ... + 27642792.

It is an arithmetic number, because the mean of its divisors is an integer number (55285580).

Almost surely, 2^165856737 is an apocalyptic number.

It is an amenable number.

165856737 is a deficient number, since it is larger than the sum of its proper divisors (55285583).

165856737 is an equidigital number, since it uses as much as digits as its factorization.

165856737 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55285582.

The product of its digits is 1058400, while the sum is 48.

The square root of 165856737 is about 12878.5378440256. The cubic root of 165856737 is about 549.4283172804.

It can be divided in two parts, 16 and 5856737, that added together give a triangular number (5856753 = T₃₄₂₂).

The spelling of 165856737 in words is "one hundred sixty-five million, eight hundred fifty-six thousand, seven hundred thirty-seven".