256402151017 has 2 divisors, whose sum is σ = 256402151018. Its totient is φ = 256402151016.

The previous prime is 256402150993. The next prime is 256402151029. The reversal of 256402151017 is 710151204652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 136287227241 + 120114923776 = 369171^2 + 346576^2 .

It is a cyclic number.

It is not a de Polignac number, because 256402151017 - 2¹⁹ = 256401626729 is a prime.

It is a super-2 number, since 2×256402151017² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (256402151077) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128201075508 + 128201075509.

It is an arithmetic number, because the mean of its divisors is an integer number (128201075509).

Almost surely, 2^256402151017 is an apocalyptic number.

It is an amenable number.

256402151017 is a deficient number, since it is larger than the sum of its proper divisors (1).

256402151017 is an equidigital number, since it uses as much as digits as its factorization.

256402151017 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16800, while the sum is 34.

Adding to 256402151017 its reverse (710151204652), we get a palindrome (966553355669).

The spelling of 256402151017 in words is "two hundred fifty-six billion, four hundred two million, one hundred fifty-one thousand, seventeen".