315500721131 has 2 divisors, whose sum is σ = 315500721132. Its totient is φ = 315500721130.

The previous prime is 315500721097. The next prime is 315500721187. The reversal of 315500721131 is 131127005513.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 315500721131 - 2¹⁴ = 315500704747 is a prime.

It is a super-2 number, since 2×315500721131² (a number of 24 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 315500721094 and 315500721103.

It is not a weakly prime, because it can be changed into another prime (315500751131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 157750360565 + 157750360566.

It is an arithmetic number, because the mean of its divisors is an integer number (157750360566).

Almost surely, 2^315500721131 is an apocalyptic number.

315500721131 is a deficient number, since it is larger than the sum of its proper divisors (1).

315500721131 is an equidigital number, since it uses as much as digits as its factorization.

315500721131 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3150, while the sum is 29.

Adding to 315500721131 its reverse (131127005513), we get a palindrome (446627726644).

The spelling of 315500721131 in words is "three hundred fifteen billion, five hundred million, seven hundred twenty-one thousand, one hundred thirty-one".