999999198 has 48 divisors (see below), whose sum is σ = 2466412416. Its totient is φ = 289853520.

The previous prime is 999999197. The next prime is 999999223. The reversal of 999999198 is 891999999.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999999191) 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 in 23 ways as a sum of consecutive naturals, for example, 105240 + ... + 114347.

It is an arithmetic number, because the mean of its divisors is an integer number (51383592).

Almost surely, 2^999999198 is an apocalyptic number.

999999198 is an abundant number, since it is smaller than the sum of its proper divisors (1466413218).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

999999198 is a wasteful number, since it uses less digits than its factorization.

999999198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 219629 (or 219626 counting only the distinct ones).

The product of its digits is 38263752, while the sum is 72.

The square root of 999999198 is about 31622.7639209478. The cubic root of 999999198 is about 999.9997326666. Note that the first 3 decimals are identical.

The spelling of 999999198 in words is "nine hundred ninety-nine million, nine hundred ninety-nine thousand, one hundred ninety-eight".