256958389 has 2 divisors, whose sum is σ = 256958390. Its totient is φ = 256958388.

The previous prime is 256958327. The next prime is 256958407. The reversal of 256958389 is 983859652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 201157489 + 55800900 = 14183^2 + 7470^2 .

It is a cyclic number.

It is not a de Polignac number, because 256958389 - 2¹⁵ = 256925621 is a prime.

It is a super-2 number, since 2×256958389² = 132055227354950642, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256958309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128479194 + 128479195.

It is an arithmetic number, because the mean of its divisors is an integer number (128479195).

Almost surely, 2^256958389 is an apocalyptic number.

It is an amenable number.

256958389 is a deficient number, since it is larger than the sum of its proper divisors (1).

256958389 is an equidigital number, since it uses as much as digits as its factorization.

256958389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4665600, while the sum is 55.

The square root of 256958389 is about 16029.9216779122. The cubic root of 256958389 is about 635.7518026374.

The spelling of 256958389 in words is "two hundred fifty-six million, nine hundred fifty-eight thousand, three hundred eighty-nine".