1256256257 has 2 divisors, whose sum is σ = 1256256258. Its totient is φ = 1256256256.

The previous prime is 1256256247. The next prime is 1256256263. The reversal of 1256256257 is 7526526521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1071187441 + 185068816 = 32729^2 + 13604^2 .

It is a cyclic number.

It is not a de Polignac number, because 1256256257 - 2⁴ = 1256256241 is a prime.

It is not a weakly prime, because it can be changed into another prime (1256256247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628128128 + 628128129.

It is an arithmetic number, because the mean of its divisors is an integer number (628128129).

Almost surely, 2^1256256257 is an apocalyptic number.

It is an amenable number.

1256256257 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256256257 is an equidigital number, since it uses as much as digits as its factorization.

1256256257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 252000, while the sum is 41.

The square root of 1256256257 is about 35443.7054637350. The cubic root of 1256256257 is about 1079.0115146752.

The spelling of 1256256257 in words is "one billion, two hundred fifty-six million, two hundred fifty-six thousand, two hundred fifty-seven".