1256347249 has 2 divisors, whose sum is σ = 1256347250. Its totient is φ = 1256347248.

The previous prime is 1256347231. The next prime is 1256347283. The reversal of 1256347249 is 9427436521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 879715600 + 376631649 = 29660^2 + 19407^2 .

It is a cyclic number.

It is not a de Polignac number, because 1256347249 - 2¹¹ = 1256345201 is a prime.

It is not a weakly prime, because it can be changed into another prime (1256347049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628173624 + 628173625.

It is an arithmetic number, because the mean of its divisors is an integer number (628173625).

Almost surely, 2^1256347249 is an apocalyptic number.

It is an amenable number.

1256347249 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256347249 is an equidigital number, since it uses as much as digits as its factorization.

1256347249 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 362880, while the sum is 43.

The square root of 1256347249 is about 35444.9890534614. The cubic root of 1256347249 is about 1079.0375653701.

The spelling of 1256347249 in words is "one billion, two hundred fifty-six million, three hundred forty-seven thousand, two hundred forty-nine".