315517253136781 has 2 divisors, whose sum is σ = 315517253136782. Its totient is φ = 315517253136780.

The previous prime is 315517253136763. The next prime is 315517253136817. The reversal of 315517253136781 is 187631352715513.

Together with next prime (315517253136817) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 186919044923556 + 128598208213225 = 13671834^2 + 11340115^2 .

It is a cyclic number.

It is not a de Polignac number, because 315517253136781 - 2⁵ = 315517253136749 is a prime.

It is a super-2 number, since 2×315517253136781² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (315517253136731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 157758626568390 + 157758626568391.

It is an arithmetic number, because the mean of its divisors is an integer number (157758626568391).

Almost surely, 2^{315517253136781} is an apocalyptic number.

It is an amenable number.

315517253136781 is a deficient number, since it is larger than the sum of its proper divisors (1).

315517253136781 is an equidigital number, since it uses as much as digits as its factorization.

315517253136781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15876000, while the sum is 58.

The spelling of 315517253136781 in words is "three hundred fifteen trillion, five hundred seventeen billion, two hundred fifty-three million, one hundred thirty-six thousand, seven hundred eighty-one".