256399783 has 2 divisors, whose sum is σ = 256399784. Its totient is φ = 256399782.

The previous prime is 256399777. The next prime is 256399799. The reversal of 256399783 is 387993652.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256399783 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 256399783.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256399483) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128199891 + 128199892.

It is an arithmetic number, because the mean of its divisors is an integer number (128199892).

Almost surely, 2^256399783 is an apocalyptic number.

256399783 is a deficient number, since it is larger than the sum of its proper divisors (1).

256399783 is an equidigital number, since it uses as much as digits as its factorization.

256399783 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2449440, while the sum is 52.

The square root of 256399783 is about 16012.4883450387. The cubic root of 256399783 is about 635.2907780223.

The spelling of 256399783 in words is "two hundred fifty-six million, three hundred ninety-nine thousand, seven hundred eighty-three".