251117245513 has 2 divisors, whose sum is σ = 251117245514. Its totient is φ = 251117245512.

The previous prime is 251117245439. The next prime is 251117245529. The reversal of 251117245513 is 315542711152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 166499089849 + 84618155664 = 408043^2 + 290892^2 .

It is a cyclic number.

It is not a de Polignac number, because 251117245513 - 2²⁵ = 251083691081 is a prime.

It is not a weakly prime, because it can be changed into another prime (251117245583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125558622756 + 125558622757.

It is an arithmetic number, because the mean of its divisors is an integer number (125558622757).

Almost surely, 2^251117245513 is an apocalyptic number.

It is an amenable number.

251117245513 is a deficient number, since it is larger than the sum of its proper divisors (1).

251117245513 is an equidigital number, since it uses as much as digits as its factorization.

251117245513 is an evil number, because the sum of its binary digits is even.

The product of its digits is 42000, while the sum is 37.

Adding to 251117245513 its reverse (315542711152), we get a palindrome (566659956665).

The spelling of 251117245513 in words is "two hundred fifty-one billion, one hundred seventeen million, two hundred forty-five thousand, five hundred thirteen".