198745581689 has 2 divisors, whose sum is σ = 198745581690. Its totient is φ = 198745581688.

The previous prime is 198745581623. The next prime is 198745581779. The reversal of 198745581689 is 986185547891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 160048003600 + 38697578089 = 400060^2 + 196717^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-198745581689 is a prime.

It is not a weakly prime, because it can be changed into another prime (198745583689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99372790844 + 99372790845.

It is an arithmetic number, because the mean of its divisors is an integer number (99372790845).

Almost surely, 2^198745581689 is an apocalyptic number.

It is an amenable number.

198745581689 is a deficient number, since it is larger than the sum of its proper divisors (1).

198745581689 is an equidigital number, since it uses as much as digits as its factorization.

198745581689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 174182400, while the sum is 71.

The spelling of 198745581689 in words is "one hundred ninety-eight billion, seven hundred forty-five million, five hundred eighty-one thousand, six hundred eighty-nine".