1256256413 has 2 divisors, whose sum is σ = 1256256414. Its totient is φ = 1256256412.

The previous prime is 1256256371. The next prime is 1256256457. The reversal of 1256256413 is 3146526521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 956170084 + 300086329 = 30922^2 + 17323^2 .

It is a cyclic number.

It is not a de Polignac number, because 1256256413 - 2¹⁰ = 1256255389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1256256473) 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, 628128206 + 628128207.

It is an arithmetic number, because the mean of its divisors is an integer number (628128207).

Almost surely, 2^1256256413 is an apocalyptic number.

It is an amenable number.

1256256413 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256256413 is an equidigital number, since it uses as much as digits as its factorization.

1256256413 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 43200, while the sum is 35.

The square root of 1256256413 is about 35443.7076644078. The cubic root of 1256256413 is about 1079.0115593385.

The spelling of 1256256413 in words is "one billion, two hundred fifty-six million, two hundred fifty-six thousand, four hundred thirteen".