1256100257 has 2 divisors, whose sum is σ = 1256100258. Its totient is φ = 1256100256.

The previous prime is 1256100119. The next prime is 1256100271. The reversal of 1256100257 is 7520016521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1118835601 + 137264656 = 33449^2 + 11716^2 .

It is a cyclic number.

It is not a de Polignac number, because 1256100257 - 2²⁸ = 987664801 is a prime.

It is not a weakly prime, because it can be changed into another prime (1256100277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628050128 + 628050129.

It is an arithmetic number, because the mean of its divisors is an integer number (628050129).

Almost surely, 2^1256100257 is an apocalyptic number.

It is an amenable number.

1256100257 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256100257 is an equidigital number, since it uses as much as digits as its factorization.

1256100257 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4200, while the sum is 29.

The square root of 1256100257 is about 35441.5047225707. The cubic root of 1256100257 is about 1078.9668494876.

Adding to 1256100257 its reverse (7520016521), we get a palindrome (8776116778).

The spelling of 1256100257 in words is "one billion, two hundred fifty-six million, one hundred thousand, two hundred fifty-seven".