Subtracting from 999999998 its reverse (899999999), we obtain a palindrome (99999999).
It is a sphenic number, since it is the product of 3 distinct primes.
It is a nialpdrome in base 10.
It is a congruent number.
It is an unprimeable number.
Almost surely, 2999999998 is an apocalyptic number.
999999998 is a wasteful number, since it uses less digits than its factorization.
999999998 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 724282.
The square root of 999999998 is about 31622.7765700610. The cubic root of 999999998 is about 999.9999993333. Note that the first 6 decimals are identical.
The spelling of 999999998 in words is "nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred ninety-eight".