256211281 has 2 divisors, whose sum is σ = 256211282. Its totient is φ = 256211280.

The previous prime is 256211279. The next prime is 256211309. The reversal of 256211281 is 182112652.

It is an a-pointer prime, because the next prime (256211309) can be obtained adding 256211281 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 201214225 + 54997056 = 14185^2 + 7416^2 .

It is a cyclic number.

It is not a de Polignac number, because 256211281 - 2¹ = 256211279 is a prime.

It is a super-2 number, since 2×256211281² = 131288441023321922, which contains 22 as substring.

Together with 256211279, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (256211261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128105640 + 128105641.

It is an arithmetic number, because the mean of its divisors is an integer number (128105641).

Almost surely, 2^256211281 is an apocalyptic number.

It is an amenable number.

256211281 is a deficient number, since it is larger than the sum of its proper divisors (1).

256211281 is an equidigital number, since it uses as much as digits as its factorization.

256211281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1920, while the sum is 28.

The square root of 256211281 is about 16006.6011695175. The cubic root of 256211281 is about 635.1350538378.

The spelling of 256211281 in words is "two hundred fifty-six million, two hundred eleven thousand, two hundred eighty-one".