1198978889 has 2 divisors, whose sum is σ = 1198978890. Its totient is φ = 1198978888.

The previous prime is 1198978877. The next prime is 1198978919. The reversal of 1198978889 is 9888798911.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 912523264 + 286455625 = 30208^2 + 16925^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1198978889 is a prime.

It is not a weakly prime, because it can be changed into another prime (1198978849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 599489444 + 599489445.

It is an arithmetic number, because the mean of its divisors is an integer number (599489445).

Almost surely, 2^1198978889 is an apocalyptic number.

It is an amenable number.

1198978889 is a deficient number, since it is larger than the sum of its proper divisors (1).

1198978889 is an equidigital number, since it uses as much as digits as its factorization.

1198978889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20901888, while the sum is 68.

The square root of 1198978889 is about 34626.2745469391. The cubic root of 1198978889 is about 1062.3570691055.

The spelling of 1198978889 in words is "one billion, one hundred ninety-eight million, nine hundred seventy-eight thousand, eight hundred eighty-nine".