256547729 has 2 divisors, whose sum is σ = 256547730. Its totient is φ = 256547728.

The previous prime is 256547699. The next prime is 256547743. The reversal of 256547729 is 927745652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 133448704 + 123099025 = 11552^2 + 11095^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256547729 is a prime.

It is not a weakly prime, because it can be changed into another prime (256547429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128273864 + 128273865.

It is an arithmetic number, because the mean of its divisors is an integer number (128273865).

Almost surely, 2^256547729 is an apocalyptic number.

It is an amenable number.

256547729 is a deficient number, since it is larger than the sum of its proper divisors (1).

256547729 is an equidigital number, since it uses as much as digits as its factorization.

256547729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1058400, while the sum is 47.

The square root of 256547729 is about 16017.1073855425. The cubic root of 256547729 is about 635.4129448673.

The spelling of 256547729 in words is "two hundred fifty-six million, five hundred forty-seven thousand, seven hundred twenty-nine".