1256457812969 has 2 divisors, whose sum is σ = 1256457812970. Its totient is φ = 1256457812968.

The previous prime is 1256457812959. The next prime is 1256457813011. The reversal of 1256457812969 is 9692187546521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 962433595369 + 294024217600 = 981037^2 + 542240^2 .

It is a cyclic number.

It is not a de Polignac number, because 1256457812969 - 2⁸ = 1256457812713 is a prime.

It is a super-2 number, since 2×1256457812969² (a number of 25 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1256457812959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628228906484 + 628228906485.

It is an arithmetic number, because the mean of its divisors is an integer number (628228906485).

Almost surely, 2^{1256457812969} is an apocalyptic number.

It is an amenable number.

1256457812969 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256457812969 is an equidigital number, since it uses as much as digits as its factorization.

1256457812969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 65318400, while the sum is 65.

The spelling of 1256457812969 in words is "one trillion, two hundred fifty-six billion, four hundred fifty-seven million, eight hundred twelve thousand, nine hundred sixty-nine".