256442171 has 2 divisors, whose sum is σ = 256442172. Its totient is φ = 256442170.

The previous prime is 256442149. The next prime is 256442201. The reversal of 256442171 is 171244652.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256442171 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (256442141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128221085 + 128221086.

It is an arithmetic number, because the mean of its divisors is an integer number (128221086).

Almost surely, 2^256442171 is an apocalyptic number.

256442171 is a deficient number, since it is larger than the sum of its proper divisors (1).

256442171 is an equidigital number, since it uses as much as digits as its factorization.

256442171 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13440, while the sum is 32.

The square root of 256442171 is about 16013.8118822471. The cubic root of 256442171 is about 635.3257848404.

The spelling of 256442171 in words is "two hundred fifty-six million, four hundred forty-two thousand, one hundred seventy-one".