256805429 has 2 divisors, whose sum is σ = 256805430. Its totient is φ = 256805428.

The previous prime is 256805413. The next prime is 256805431. The reversal of 256805429 is 924508652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 249703204 + 7102225 = 15802^2 + 2665^2 .

It is a cyclic number.

It is not a de Polignac number, because 256805429 - 2⁴ = 256805413 is a prime.

Together with 256805431, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256805489) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128402714 + 128402715.

It is an arithmetic number, because the mean of its divisors is an integer number (128402715).

Almost surely, 2^256805429 is an apocalyptic number.

It is an amenable number.

256805429 is a deficient number, since it is larger than the sum of its proper divisors (1).

256805429 is an equidigital number, since it uses as much as digits as its factorization.

256805429 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 172800, while the sum is 41.

The square root of 256805429 is about 16025.1498900946. The cubic root of 256805429 is about 635.6256292932.

The spelling of 256805429 in words is "two hundred fifty-six million, eight hundred five thousand, four hundred twenty-nine".