18818686837 has 2 divisors, whose sum is σ = 18818686838. Its totient is φ = 18818686836.

The previous prime is 18818686811. The next prime is 18818686847. The reversal of 18818686837 is 73868681881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16985648241 + 1833038596 = 130329^2 + 42814^2 .

It is a cyclic number.

It is not a de Polignac number, because 18818686837 - 2⁷ = 18818686709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18818686807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9409343418 + 9409343419.

It is an arithmetic number, because the mean of its divisors is an integer number (9409343419).

Almost surely, 2^18818686837 is an apocalyptic number.

It is an amenable number.

18818686837 is a deficient number, since it is larger than the sum of its proper divisors (1).

18818686837 is an equidigital number, since it uses as much as digits as its factorization.

18818686837 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24772608, while the sum is 64.

The spelling of 18818686837 in words is "eighteen billion, eight hundred eighteen million, six hundred eighty-six thousand, eight hundred thirty-seven".