256984817 has 2 divisors, whose sum is σ = 256984818. Its totient is φ = 256984816.

The previous prime is 256984799. The next prime is 256984829. The reversal of 256984817 is 718489652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 247244176 + 9740641 = 15724^2 + 3121^2 .

It is a cyclic number.

It is not a de Polignac number, because 256984817 - 2⁸ = 256984561 is a prime.

It is not a weakly prime, because it can be changed into another prime (256984877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128492408 + 128492409.

It is an arithmetic number, because the mean of its divisors is an integer number (128492409).

Almost surely, 2^256984817 is an apocalyptic number.

It is an amenable number.

256984817 is a deficient number, since it is larger than the sum of its proper divisors (1).

256984817 is an equidigital number, since it uses as much as digits as its factorization.

256984817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 967680, while the sum is 50.

The square root of 256984817 is about 16030.7459901278. The cubic root of 256984817 is about 635.7735974407.

The spelling of 256984817 in words is "two hundred fifty-six million, nine hundred eighty-four thousand, eight hundred seventeen".