18505431319 has 2 divisors, whose sum is σ = 18505431320. Its totient is φ = 18505431318.

The previous prime is 18505431253. The next prime is 18505431323. The reversal of 18505431319 is 91313450581.

It is a strong prime.

It is an emirp because it is prime and its reverse (91313450581) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18505431319 is a prime.

It is a super-2 number, since 2×18505431319² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18505431359) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9252715659 + 9252715660.

It is an arithmetic number, because the mean of its divisors is an integer number (9252715660).

Almost surely, 2^18505431319 is an apocalyptic number.

18505431319 is a deficient number, since it is larger than the sum of its proper divisors (1).

18505431319 is an equidigital number, since it uses as much as digits as its factorization.

18505431319 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64800, while the sum is 40.

The spelling of 18505431319 in words is "eighteen billion, five hundred five million, four hundred thirty-one thousand, three hundred nineteen".