256778783 has 2 divisors, whose sum is σ = 256778784. Its totient is φ = 256778782.

The previous prime is 256778759. The next prime is 256778803. The reversal of 256778783 is 387877652.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 256778783 - 2⁸ = 256778527 is a prime.

It is a super-2 number, since 2×256778783² = 131870686797922178, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256778713) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128389391 + 128389392.

It is an arithmetic number, because the mean of its divisors is an integer number (128389392).

Almost surely, 2^256778783 is an apocalyptic number.

256778783 is a deficient number, since it is larger than the sum of its proper divisors (1).

256778783 is an equidigital number, since it uses as much as digits as its factorization.

256778783 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3951360, while the sum is 53.

The square root of 256778783 is about 16024.3184878484. The cubic root of 256778783 is about 635.6036444694.

The spelling of 256778783 in words is "two hundred fifty-six million, seven hundred seventy-eight thousand, seven hundred eighty-three".