256136213331 has 12 divisors (see below), whose sum is σ = 369979605840. Its totient is φ = 170755133040.

The previous prime is 256136213317. The next prime is 256136213419. The reversal of 256136213331 is 133312631652.

256136213331 is a `hidden beast` number, since 2 + 5 + 613 + 6 + 2 + 1 + 3 + 3 + 31 = 666.

It is not a de Polignac number, because 256136213331 - 2⁵ = 256136213299 is a prime.

It is a super-2 number, since 2×256136213331² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (256136223331) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 726186 + ... + 1019616.

It is an arithmetic number, because the mean of its divisors is an integer number (30831633820).

Almost surely, 2^256136213331 is an apocalyptic number.

256136213331 is a deficient number, since it is larger than the sum of its proper divisors (113843392509).

256136213331 is a wasteful number, since it uses less digits than its factorization.

256136213331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390426 (or 390423 counting only the distinct ones).

The product of its digits is 58320, while the sum is 36.

Adding to 256136213331 its reverse (133312631652), we get a palindrome (389448844983).

The spelling of 256136213331 in words is "two hundred fifty-six billion, one hundred thirty-six million, two hundred thirteen thousand, three hundred thirty-one".