256385747 has 2 divisors, whose sum is σ = 256385748. Its totient is φ = 256385746.

The previous prime is 256385719. The next prime is 256385749. The reversal of 256385747 is 747583652.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 256385747 - 2¹⁴ = 256369363 is a prime.

Together with 256385749, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (256385749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128192873 + 128192874.

It is an arithmetic number, because the mean of its divisors is an integer number (128192874).

Almost surely, 2^256385747 is an apocalyptic number.

256385747 is a deficient number, since it is larger than the sum of its proper divisors (1).

256385747 is an equidigital number, since it uses as much as digits as its factorization.

256385747 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1411200, while the sum is 47.

The square root of 256385747 is about 16012.0500561296. The cubic root of 256385747 is about 635.2791853135.

The spelling of 256385747 in words is "two hundred fifty-six million, three hundred eighty-five thousand, seven hundred forty-seven".