18846643397 has 2 divisors, whose sum is σ = 18846643398. Its totient is φ = 18846643396.

The previous prime is 18846643393. The next prime is 18846643423. The reversal of 18846643397 is 79334664881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18494368036 + 352275361 = 135994^2 + 18769^2 .

It is a cyclic number.

It is not a de Polignac number, because 18846643397 - 2² = 18846643393 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18846643393) 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, 9423321698 + 9423321699.

It is an arithmetic number, because the mean of its divisors is an integer number (9423321699).

Almost surely, 2^18846643397 is an apocalyptic number.

It is an amenable number.

18846643397 is a deficient number, since it is larger than the sum of its proper divisors (1).

18846643397 is an equidigital number, since it uses as much as digits as its factorization.

18846643397 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20901888, while the sum is 59.

The spelling of 18846643397 in words is "eighteen billion, eight hundred forty-six million, six hundred forty-three thousand, three hundred ninety-seven".