It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 368999999 = 2459 ⋅150061.
It is a cyclic number.
It is a Duffinian number.
It is a nialpdrome in base 10.
It is a congruent number.
Almost surely, 2999999863 is an apocalyptic number.
999999863 is a wasteful number, since it uses less digits than its factorization.
999999863 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 64824.
The square root of 999999863 is about 31622.7744355235. The cubic root of 999999863 is about 999.9999543333. Note that the first 4 decimals are identical.
The spelling of 999999863 in words is "nine hundred ninety-nine million, nine hundred ninety-nine thousand, eight hundred sixty-three".