18657894049 has 2 divisors, whose sum is σ = 18657894050. Its totient is φ = 18657894048.

The previous prime is 18657894023. The next prime is 18657894083. The reversal of 18657894049 is 94049875681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9946471824 + 8711422225 = 99732^2 + 93335^2 .

It is an emirp because it is prime and its reverse (94049875681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18657894049 - 2¹⁹ = 18657369761 is a prime.

It is a super-2 number, since 2×18657894049² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18657894649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9328947024 + 9328947025.

It is an arithmetic number, because the mean of its divisors is an integer number (9328947025).

Almost surely, 2^18657894049 is an apocalyptic number.

It is an amenable number.

18657894049 is a deficient number, since it is larger than the sum of its proper divisors (1).

18657894049 is an equidigital number, since it uses as much as digits as its factorization.

18657894049 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17418240, while the sum is 61.

The spelling of 18657894049 in words is "eighteen billion, six hundred fifty-seven million, eight hundred ninety-four thousand, forty-nine".