256559773 has 2 divisors, whose sum is σ = 256559774. Its totient is φ = 256559772.

The previous prime is 256559747. The next prime is 256559777. The reversal of 256559773 is 377955652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 239692324 + 16867449 = 15482^2 + 4107^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256559773 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256559777) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128279886 + 128279887.

It is an arithmetic number, because the mean of its divisors is an integer number (128279887).

Almost surely, 2^256559773 is an apocalyptic number.

It is an amenable number.

256559773 is a deficient number, since it is larger than the sum of its proper divisors (1).

256559773 is an equidigital number, since it uses as much as digits as its factorization.

256559773 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1984500, while the sum is 49.

The square root of 256559773 is about 16017.4833541353. The cubic root of 256559773 is about 635.4228881682.

The spelling of 256559773 in words is "two hundred fifty-six million, five hundred fifty-nine thousand, seven hundred seventy-three".