161312513 has 2 divisors, whose sum is σ = 161312514. Its totient is φ = 161312512.

The previous prime is 161312509. The next prime is 161312521. The reversal of 161312513 is 315213161.

161312513 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 136142224 + 25170289 = 11668^2 + 5017^2 .

It is a cyclic number.

It is not a de Polignac number, because 161312513 - 2² = 161312509 is a prime.

It is not a weakly prime, because it can be changed into another prime (161312533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80656256 + 80656257.

It is an arithmetic number, because the mean of its divisors is an integer number (80656257).

Almost surely, 2^161312513 is an apocalyptic number.

It is an amenable number.

161312513 is a deficient number, since it is larger than the sum of its proper divisors (1).

161312513 is an equidigital number, since it uses as much as digits as its factorization.

161312513 is an evil number, because the sum of its binary digits is even.

The product of its digits is 540, while the sum is 23.

The square root of 161312513 is about 12700.8863076559. The cubic root of 161312513 is about 544.3639444388.

Adding to 161312513 its reverse (315213161), we get a palindrome (476525674).

The spelling of 161312513 in words is "one hundred sixty-one million, three hundred twelve thousand, five hundred thirteen".