256665271 has 2 divisors, whose sum is σ = 256665272. Its totient is φ = 256665270.

The previous prime is 256665229. The next prime is 256665313. The reversal of 256665271 is 172566652.

It is a balanced prime because it is at equal distance from previous prime (256665229) and next prime (256665313).

It is a cyclic number.

It is not a de Polignac number, because 256665271 - 2²³ = 248276663 is a prime.

It is a super-2 number, since 2×256665271² = 131754122675006882, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256665971) 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 as a sum of consecutive naturals, namely, 128332635 + 128332636.

It is an arithmetic number, because the mean of its divisors is an integer number (128332636).

Almost surely, 2^256665271 is an apocalyptic number.

256665271 is a deficient number, since it is larger than the sum of its proper divisors (1).

256665271 is an equidigital number, since it uses as much as digits as its factorization.

256665271 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 151200, while the sum is 40.

The square root of 256665271 is about 16020.7762296338. The cubic root of 256665271 is about 635.5099720431.

The spelling of 256665271 in words is "two hundred fifty-six million, six hundred sixty-five thousand, two hundred seventy-one".