198393903989 has 2 divisors, whose sum is σ = 198393903990. Its totient is φ = 198393903988.

The previous prime is 198393903973. The next prime is 198393904019. The reversal of 198393903989 is 989309393891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 126547390225 + 71846513764 = 355735^2 + 268042^2 .

It is a cyclic number.

It is not a de Polignac number, because 198393903989 - 2⁴ = 198393903973 is a prime.

It is a super-2 number, since 2×198393903989² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (198393903289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99196951994 + 99196951995.

It is an arithmetic number, because the mean of its divisors is an integer number (99196951995).

Almost surely, 2^198393903989 is an apocalyptic number.

It is an amenable number.

198393903989 is a deficient number, since it is larger than the sum of its proper divisors (1).

198393903989 is an equidigital number, since it uses as much as digits as its factorization.

198393903989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 102036672, while the sum is 71.

The spelling of 198393903989 in words is "one hundred ninety-eight billion, three hundred ninety-three million, nine hundred three thousand, nine hundred eighty-nine".