256696217 has 2 divisors, whose sum is σ = 256696218. Its totient is φ = 256696216.

The previous prime is 256696183. The next prime is 256696249. The reversal of 256696217 is 712696652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 210714256 + 45981961 = 14516^2 + 6781^2 .

It is a cyclic number.

It is not a de Polignac number, because 256696217 - 2¹⁴ = 256679833 is a prime.

It is a super-2 number, since 2×256696217² = 131785895644222178, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (256696117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128348108 + 128348109.

It is an arithmetic number, because the mean of its divisors is an integer number (128348109).

Almost surely, 2^256696217 is an apocalyptic number.

It is an amenable number.

256696217 is a deficient number, since it is larger than the sum of its proper divisors (1).

256696217 is an equidigital number, since it uses as much as digits as its factorization.

256696217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 272160, while the sum is 44.

The square root of 256696217 is about 16021.7420089078. The cubic root of 256696217 is about 635.5355120537.

The spelling of 256696217 in words is "two hundred fifty-six million, six hundred ninety-six thousand, two hundred seventeen".