256165851 has 4 divisors (see below), whose sum is σ = 341554472. Its totient is φ = 170777232.

The previous prime is 256165849. The next prime is 256165859. The reversal of 256165851 is 158561652.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 256165851 - 2¹ = 256165849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256165859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42694306 + ... + 42694311.

It is an arithmetic number, because the mean of its divisors is an integer number (85388618).

Almost surely, 2^256165851 is an apocalyptic number.

256165851 is a deficient number, since it is larger than the sum of its proper divisors (85388621).

256165851 is an equidigital number, since it uses as much as digits as its factorization.

256165851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85388620.

The product of its digits is 72000, while the sum is 39.

The square root of 256165851 is about 16005.1820045884. The cubic root of 256165851 is about 635.0975120468.

The spelling of 256165851 in words is "two hundred fifty-six million, one hundred sixty-five thousand, eight hundred fifty-one".