18199820189 has 2 divisors, whose sum is σ = 18199820190. Its totient is φ = 18199820188.

The previous prime is 18199820179. The next prime is 18199820201. The reversal of 18199820189 is 98102899181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10549344100 + 7650476089 = 102710^2 + 87467^2 .

It is a cyclic number.

It is not a de Polignac number, because 18199820189 - 2⁸ = 18199819933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18199820159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9099910094 + 9099910095.

It is an arithmetic number, because the mean of its divisors is an integer number (9099910095).

Almost surely, 2^18199820189 is an apocalyptic number.

It is an amenable number.

18199820189 is a deficient number, since it is larger than the sum of its proper divisors (1).

18199820189 is an equidigital number, since it uses as much as digits as its factorization.

18199820189 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 746496, while the sum is 56.

The spelling of 18199820189 in words is "eighteen billion, one hundred ninety-nine million, eight hundred twenty thousand, one hundred eighty-nine".