1256133313 has 4 divisors (see below), whose sum is σ = 1290082900. Its totient is φ = 1222183728.

The previous prime is 1256133311. The next prime is 1256133317. The reversal of 1256133313 is 3133316521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3133316521 = 181 ⋅17311141.

It can be written as a sum of positive squares in 2 ways, for example, as 1045099584 + 211033729 = 32328^2 + 14527^2 .

It is a cyclic number.

It is not a de Polignac number, because 1256133313 - 2¹ = 1256133311 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1256133311) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16974738 + ... + 16974811.

It is an arithmetic number, because the mean of its divisors is an integer number (322520725).

Almost surely, 2^1256133313 is an apocalyptic number.

It is an amenable number.

1256133313 is a deficient number, since it is larger than the sum of its proper divisors (33949587).

1256133313 is an equidigital number, since it uses as much as digits as its factorization.

1256133313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33949586.

The product of its digits is 4860, while the sum is 28.

The square root of 1256133313 is about 35441.9710653908. The cubic root of 1256133313 is about 1078.9763142351.

Adding to 1256133313 its reverse (3133316521), we get a palindrome (4389449834).

The spelling of 1256133313 in words is "one billion, two hundred fifty-six million, one hundred thirty-three thousand, three hundred thirteen".