256051217 has 2 divisors, whose sum is σ = 256051218. Its totient is φ = 256051216.

The previous prime is 256051199. The next prime is 256051231. The reversal of 256051217 is 712150652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 163814401 + 92236816 = 12799^2 + 9604^2 .

It is a cyclic number.

It is not a de Polignac number, because 256051217 - 2⁸ = 256050961 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 256051217.

It is not a weakly prime, because it can be changed into another prime (256051267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128025608 + 128025609.

It is an arithmetic number, because the mean of its divisors is an integer number (128025609).

Almost surely, 2^256051217 is an apocalyptic number.

It is an amenable number.

256051217 is a deficient number, since it is larger than the sum of its proper divisors (1).

256051217 is an equidigital number, since it uses as much as digits as its factorization.

256051217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4200, while the sum is 29.

The square root of 256051217 is about 16001.6004512049. The cubic root of 256051217 is about 635.0027627135.

The spelling of 256051217 in words is "two hundred fifty-six million, fifty-one thousand, two hundred seventeen".