18663619937 has 2 divisors, whose sum is σ = 18663619938. Its totient is φ = 18663619936.

The previous prime is 18663619903. The next prime is 18663619973. The reversal of 18663619937 is 73991636681.

Together with next prime (18663619973) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13633831696 + 5029788241 = 116764^2 + 70921^2 .

It is an emirp because it is prime and its reverse (73991636681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18663619937 - 2²⁸ = 18395184481 is a prime.

It is a super-3 number, since 3×18663619937³ (a number of 32 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (18663610937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9331809968 + 9331809969.

It is an arithmetic number, because the mean of its divisors is an integer number (9331809969).

Almost surely, 2^18663619937 is an apocalyptic number.

It is an amenable number.

18663619937 is a deficient number, since it is larger than the sum of its proper divisors (1).

18663619937 is an equidigital number, since it uses as much as digits as its factorization.

18663619937 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8817984, while the sum is 59.

The spelling of 18663619937 in words is "eighteen billion, six hundred sixty-three million, six hundred nineteen thousand, nine hundred thirty-seven".