256068781 has 2 divisors, whose sum is σ = 256068782. Its totient is φ = 256068780.

The previous prime is 256068767. The next prime is 256068797. The reversal of 256068781 is 187860652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 254913156 + 1155625 = 15966^2 + 1075^2 .

It is a cyclic number.

It is not a de Polignac number, because 256068781 - 2¹⁵ = 256036013 is a prime.

It is a super-2 number, since 2×256068781² = 131142441205651922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256068721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128034390 + 128034391.

It is an arithmetic number, because the mean of its divisors is an integer number (128034391).

Almost surely, 2^256068781 is an apocalyptic number.

It is an amenable number.

256068781 is a deficient number, since it is larger than the sum of its proper divisors (1).

256068781 is an equidigital number, since it uses as much as digits as its factorization.

256068781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 161280, while the sum is 43.

The square root of 256068781 is about 16002.1492618960. The cubic root of 256068781 is about 635.0172818576.

The spelling of 256068781 in words is "two hundred fifty-six million, sixty-eight thousand, seven hundred eighty-one".