18307314581 has 2 divisors, whose sum is σ = 18307314582. Its totient is φ = 18307314580.

The previous prime is 18307314539. The next prime is 18307314589. The reversal of 18307314581 is 18541370381.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16785534481 + 1521780100 = 129559^2 + 39010^2 .

It is a cyclic number.

It is not a de Polignac number, because 18307314581 - 2⁶ = 18307314517 is a prime.

It is a super-2 number, since 2×18307314581² (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 (18307314589) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9153657290 + 9153657291.

It is an arithmetic number, because the mean of its divisors is an integer number (9153657291).

Almost surely, 2^18307314581 is an apocalyptic number.

It is an amenable number.

18307314581 is a deficient number, since it is larger than the sum of its proper divisors (1).

18307314581 is an equidigital number, since it uses as much as digits as its factorization.

18307314581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 80640, while the sum is 41.

The spelling of 18307314581 in words is "eighteen billion, three hundred seven million, three hundred fourteen thousand, five hundred eighty-one".