315500721097 has 2 divisors, whose sum is σ = 315500721098. Its totient is φ = 315500721096.

The previous prime is 315500721083. The next prime is 315500721131. The reversal of 315500721097 is 790127005513.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 225065796921 + 90434924176 = 474411^2 + 300724^2 .

It is an emirp because it is prime and its reverse (790127005513) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-315500721097 is a prime.

It is not a weakly prime, because it can be changed into another prime (315500721007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 157750360548 + 157750360549.

It is an arithmetic number, because the mean of its divisors is an integer number (157750360549).

Almost surely, 2^315500721097 is an apocalyptic number.

It is an amenable number.

315500721097 is a deficient number, since it is larger than the sum of its proper divisors (1).

315500721097 is an equidigital number, since it uses as much as digits as its factorization.

315500721097 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 66150, while the sum is 40.

The spelling of 315500721097 in words is "three hundred fifteen billion, five hundred million, seven hundred twenty-one thousand, ninety-seven".