256402039 has 2 divisors, whose sum is σ = 256402040. Its totient is φ = 256402038.

The previous prime is 256402019. The next prime is 256402057. The reversal of 256402039 is 930204652.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 256402039 - 2¹⁵ = 256369271 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 256402039.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256402009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128201019 + 128201020.

It is an arithmetic number, because the mean of its divisors is an integer number (128201020).

Almost surely, 2^256402039 is an apocalyptic number.

256402039 is a deficient number, since it is larger than the sum of its proper divisors (1).

256402039 is an equidigital number, since it uses as much as digits as its factorization.

256402039 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 256402039 is about 16012.5587898999. The cubic root of 256402039 is about 635.2926412737.

The spelling of 256402039 in words is "two hundred fifty-six million, four hundred two thousand, thirty-nine".