256814617 has 2 divisors, whose sum is σ = 256814618. Its totient is φ = 256814616.

The previous prime is 256814567. The next prime is 256814629. The reversal of 256814617 is 716418652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 243484816 + 13329801 = 15604^2 + 3651^2 .

It is a cyclic number.

It is not a de Polignac number, because 256814617 - 2¹⁹ = 256290329 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 256814617.

It is not a weakly prime, because it can be changed into another prime (256814717) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128407308 + 128407309.

It is an arithmetic number, because the mean of its divisors is an integer number (128407309).

Almost surely, 2^256814617 is an apocalyptic number.

It is an amenable number.

256814617 is a deficient number, since it is larger than the sum of its proper divisors (1).

256814617 is an equidigital number, since it uses as much as digits as its factorization.

256814617 is an evil number, because the sum of its binary digits is even.

The product of its digits is 80640, while the sum is 40.

The square root of 256814617 is about 16025.4365619162. The cubic root of 256814617 is about 635.6332096867.

The spelling of 256814617 in words is "two hundred fifty-six million, eight hundred fourteen thousand, six hundred seventeen".