256778273 has 2 divisors, whose sum is σ = 256778274. Its totient is φ = 256778272.

The previous prime is 256778243. The next prime is 256778311. The reversal of 256778273 is 372877652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 243110464 + 13667809 = 15592^2 + 3697^2 .

It is a cyclic number.

It is not a de Polignac number, because 256778273 - 2⁸ = 256778017 is a prime.

It is not a weakly prime, because it can be changed into another prime (256778243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128389136 + 128389137.

It is an arithmetic number, because the mean of its divisors is an integer number (128389137).

Almost surely, 2^256778273 is an apocalyptic number.

It is an amenable number.

256778273 is a deficient number, since it is larger than the sum of its proper divisors (1).

256778273 is an equidigital number, since it uses as much as digits as its factorization.

256778273 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 987840, while the sum is 47.

The square root of 256778273 is about 16024.3025745272. The cubic root of 256778273 is about 635.6032236687.

The spelling of 256778273 in words is "two hundred fifty-six million, seven hundred seventy-eight thousand, two hundred seventy-three".