256223131 has 2 divisors, whose sum is σ = 256223132. Its totient is φ = 256223130.

The previous prime is 256223129. The next prime is 256223137. The reversal of 256223131 is 131322652.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 256223131 - 2¹ = 256223129 is a prime.

It is a super-2 number, since 2×256223131² = 131300585718886322, which contains 22 as substring.

Together with 256223129, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 256223096 and 256223105.

It is not a weakly prime, because it can be changed into another prime (256223137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128111565 + 128111566.

It is an arithmetic number, because the mean of its divisors is an integer number (128111566).

Almost surely, 2^256223131 is an apocalyptic number.

256223131 is a deficient number, since it is larger than the sum of its proper divisors (1).

256223131 is an equidigital number, since it uses as much as digits as its factorization.

256223131 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2160, while the sum is 25.

The square root of 256223131 is about 16006.9713250196. The cubic root of 256223131 is about 635.1448455408.

Adding to 256223131 its reverse (131322652), we get a palindrome (387545783).

The spelling of 256223131 in words is "two hundred fifty-six million, two hundred twenty-three thousand, one hundred thirty-one".