256973729 has 2 divisors, whose sum is σ = 256973730. Its totient is φ = 256973728.

The previous prime is 256973723. The next prime is 256973741. The reversal of 256973729 is 927379652.

It is a happy number.

256973729 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 164429329 + 92544400 = 12823^2 + 9620^2 .

It is a cyclic number.

It is not a de Polignac number, because 256973729 - 2¹⁶ = 256908193 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (256973723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128486864 + 128486865.

It is an arithmetic number, because the mean of its divisors is an integer number (128486865).

Almost surely, 2^256973729 is an apocalyptic number.

It is an amenable number.

256973729 is a deficient number, since it is larger than the sum of its proper divisors (1).

256973729 is an equidigital number, since it uses as much as digits as its factorization.

256973729 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1428840, while the sum is 50.

The square root of 256973729 is about 16030.4001509632. The cubic root of 256973729 is about 635.7644535036.

The spelling of 256973729 in words is "two hundred fifty-six million, nine hundred seventy-three thousand, seven hundred twenty-nine".