256957769 has 2 divisors, whose sum is σ = 256957770. Its totient is φ = 256957768.

The previous prime is 256957751. The next prime is 256957781. The reversal of 256957769 is 967759652.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 249229369 + 7728400 = 15787^2 + 2780^2 .

It is a cyclic number.

It is not a de Polignac number, because 256957769 - 2⁸ = 256957513 is a prime.

It is a super-2 number, since 2×256957769² = 132054590098914722, which 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 (256957069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128478884 + 128478885.

It is an arithmetic number, because the mean of its divisors is an integer number (128478885).

Almost surely, 2^256957769 is an apocalyptic number.

It is an amenable number.

256957769 is a deficient number, since it is larger than the sum of its proper divisors (1).

256957769 is an equidigital number, since it uses as much as digits as its factorization.

256957769 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7144200, while the sum is 56.

The square root of 256957769 is about 16029.9023390662. The cubic root of 256957769 is about 635.7512913141.

The spelling of 256957769 in words is "two hundred fifty-six million, nine hundred fifty-seven thousand, seven hundred sixty-nine".