251255331513 has 20 divisors (see below), whose sum is σ = 375384274980. Its totient is φ = 167480242272.

The previous prime is 251255331493. The next prime is 251255331559. The reversal of 251255331513 is 315133552152.

251255331513 is a `hidden beast` number, since 2 + 51 + 2 + 553 + 3 + 1 + 51 + 3 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 127972183824 + 123283147689 = 357732^2 + 351117^2 .

It is not a de Polignac number, because 251255331513 - 2¹² = 251255327417 is a prime.

It is a super-2 number, since 2×251255331513² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (251255331013) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 379831 + ... + 804227.

It is an arithmetic number, because the mean of its divisors is an integer number (18769213749).

Almost surely, 2^251255331513 is an apocalyptic number.

It is an amenable number.

251255331513 is a deficient number, since it is larger than the sum of its proper divisors (124128943467).

251255331513 is an equidigital number, since it uses as much as digits as its factorization.

251255331513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 431718 (or 431709 counting only the distinct ones).

The product of its digits is 67500, while the sum is 36.

Adding to 251255331513 its reverse (315133552152), we get a palindrome (566388883665).

The spelling of 251255331513 in words is "two hundred fifty-one billion, two hundred fifty-five million, three hundred thirty-one thousand, five hundred thirteen".