256222717 has 2 divisors, whose sum is σ = 256222718. Its totient is φ = 256222716.

The previous prime is 256222699. The next prime is 256222727. The reversal of 256222717 is 717222652.

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., 254530116 + 1692601 = 15954^2 + 1301^2 .

It is a cyclic number.

It is not a de Polignac number, because 256222717 - 2¹¹ = 256220669 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256222727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128111358 + 128111359.

It is an arithmetic number, because the mean of its divisors is an integer number (128111359).

Almost surely, 2^256222717 is an apocalyptic number.

It is an amenable number.

256222717 is a deficient number, since it is larger than the sum of its proper divisors (1).

256222717 is an equidigital number, since it uses as much as digits as its factorization.

256222717 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23520, while the sum is 34.

The square root of 256222717 is about 16006.9583931489. The cubic root of 256222717 is about 635.1445034561.

The spelling of 256222717 in words is "two hundred fifty-six million, two hundred twenty-two thousand, seven hundred seventeen".