256121023 has 2 divisors, whose sum is σ = 256121024. Its totient is φ = 256121022.

The previous prime is 256120981. The next prime is 256121093. The reversal of 256121023 is 320121652.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 256121023 - 2⁹ = 256120511 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 256120985 and 256121003.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256121093) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128060511 + 128060512.

It is an arithmetic number, because the mean of its divisors is an integer number (128060512).

Almost surely, 2^256121023 is an apocalyptic number.

256121023 is a deficient number, since it is larger than the sum of its proper divisors (1).

256121023 is an equidigital number, since it uses as much as digits as its factorization.

256121023 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 256121023 is about 16003.7815218779. The cubic root of 256121023 is about 635.0604633769.

Adding to 256121023 its reverse (320121652), we get a palindrome (576242675).

The spelling of 256121023 in words is "two hundred fifty-six million, one hundred twenty-one thousand, twenty-three".