256289123 has 2 divisors, whose sum is σ = 256289124. Its totient is φ = 256289122.

The previous prime is 256289113. The next prime is 256289171. The reversal of 256289123 is 321982652.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 256289123 - 2¹² = 256285027 is a prime.

It is a super-2 number, since 2×256289123² = 131368229136218258, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (256289113) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128144561 + 128144562.

It is an arithmetic number, because the mean of its divisors is an integer number (128144562).

Almost surely, 2^256289123 is an apocalyptic number.

256289123 is a deficient number, since it is larger than the sum of its proper divisors (1).

256289123 is an equidigital number, since it uses as much as digits as its factorization.

256289123 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51840, while the sum is 38.

The square root of 256289123 is about 16009.0325441608. The cubic root of 256289123 is about 635.1993694767.

The spelling of 256289123 in words is "two hundred fifty-six million, two hundred eighty-nine thousand, one hundred twenty-three".