18513323513 has 2 divisors, whose sum is σ = 18513323514. Its totient is φ = 18513323512.

The previous prime is 18513323509. The next prime is 18513323579. The reversal of 18513323513 is 31532331581.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16992947449 + 1520376064 = 130357^2 + 38992^2 .

It is a cyclic number.

It is not a de Polignac number, because 18513323513 - 2² = 18513323509 is a prime.

It is a super-2 number, since 2×18513323513² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (18513323503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9256661756 + 9256661757.

It is an arithmetic number, because the mean of its divisors is an integer number (9256661757).

Almost surely, 2^18513323513 is an apocalyptic number.

It is an amenable number.

18513323513 is a deficient number, since it is larger than the sum of its proper divisors (1).

18513323513 is an equidigital number, since it uses as much as digits as its factorization.

18513323513 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32400, while the sum is 35.

The spelling of 18513323513 in words is "eighteen billion, five hundred thirteen million, three hundred twenty-three thousand, five hundred thirteen".