198055589 has 2 divisors, whose sum is σ = 198055590. Its totient is φ = 198055588.

The previous prime is 198055579. The next prime is 198055591. The reversal of 198055589 is 985550891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 192376900 + 5678689 = 13870^2 + 2383^2 .

It is a cyclic number.

It is not a de Polignac number, because 198055589 - 2¹² = 198051493 is a prime.

It is a Sophie Germain prime.

Together with 198055591, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (198055519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99027794 + 99027795.

It is an arithmetic number, because the mean of its divisors is an integer number (99027795).

Almost surely, 2^198055589 is an apocalyptic number.

It is an amenable number.

198055589 is a deficient number, since it is larger than the sum of its proper divisors (1).

198055589 is an equidigital number, since it uses as much as digits as its factorization.

198055589 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648000, while the sum is 50.

The square root of 198055589 is about 14073.2224099529. Note that the first 3 decimals coincide. The cubic root of 198055589 is about 582.9022085396.

The spelling of 198055589 in words is "one hundred ninety-eight million, fifty-five thousand, five hundred eighty-nine".