256955173 has 2 divisors, whose sum is σ = 256955174. Its totient is φ = 256955172.

The previous prime is 256955137. The next prime is 256955197. The reversal of 256955173 is 371559652.

256955173 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

Together with previous prime (256955137) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 254785444 + 2169729 = 15962^2 + 1473^2 .

It is a cyclic number.

It is not a de Polignac number, because 256955173 - 2¹⁷ = 256824101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256955113) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128477586 + 128477587.

It is an arithmetic number, because the mean of its divisors is an integer number (128477587).

Almost surely, 2^256955173 is an apocalyptic number.

It is an amenable number.

256955173 is a deficient number, since it is larger than the sum of its proper divisors (1).

256955173 is an equidigital number, since it uses as much as digits as its factorization.

256955173 is an evil number, because the sum of its binary digits is even.

The product of its digits is 283500, while the sum is 43.

The square root of 256955173 is about 16029.8213651931. The cubic root of 256955173 is about 635.7491503450.

The spelling of 256955173 in words is "two hundred fifty-six million, nine hundred fifty-five thousand, one hundred seventy-three".