18119423981 has 2 divisors, whose sum is σ = 18119423982. Its totient is φ = 18119423980.

The previous prime is 18119423969. The next prime is 18119424053. The reversal of 18119423981 is 18932491181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15941335081 + 2178088900 = 126259^2 + 46670^2 .

It is a cyclic number.

It is not a de Polignac number, because 18119423981 - 2¹⁴ = 18119407597 is a prime.

It is a super-2 number, since 2×18119423981² (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 (18119423281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9059711990 + 9059711991.

It is an arithmetic number, because the mean of its divisors is an integer number (9059711991).

Almost surely, 2^18119423981 is an apocalyptic number.

It is an amenable number.

18119423981 is a deficient number, since it is larger than the sum of its proper divisors (1).

18119423981 is an equidigital number, since it uses as much as digits as its factorization.

18119423981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 124416, while the sum is 47.

The spelling of 18119423981 in words is "eighteen billion, one hundred nineteen million, four hundred twenty-three thousand, nine hundred eighty-one".