256406846617 has 2 divisors, whose sum is σ = 256406846618. Its totient is φ = 256406846616.

The previous prime is 256406846599. The next prime is 256406846621. The reversal of 256406846617 is 716648604652.

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., 169926152841 + 86480693776 = 412221^2 + 294076^2 .

It is a cyclic number.

It is not a de Polignac number, because 256406846617 - 2⁷ = 256406846489 is a prime.

It is not a weakly prime, because it can be changed into another prime (256406846417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128203423308 + 128203423309.

It is an arithmetic number, because the mean of its divisors is an integer number (128203423309).

Almost surely, 2^256406846617 is an apocalyptic number.

It is an amenable number.

256406846617 is a deficient number, since it is larger than the sum of its proper divisors (1).

256406846617 is an equidigital number, since it uses as much as digits as its factorization.

256406846617 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11612160, while the sum is 55.

The spelling of 256406846617 in words is "two hundred fifty-six billion, four hundred six million, eight hundred forty-six thousand, six hundred seventeen".