It is a strong prime.
It is an emirp because it is prime and its reverse (190008991) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 160008661 and 166800061.
It is a cyclic number.
It is a self number, because there is not a number n which added to its sum of digits gives 199800091.
Almost surely, 2199800091 is an apocalyptic number.
199800091 is an equidigital number, since it uses as much as digits as its factorization.
199800091 is an evil number, because the sum of its binary digits is even.
The square root of 199800091 is about 14135.0660062131. The cubic root of 199800091 is about 584.6086368668.
The spelling of 199800091 in words is "one hundred ninety-nine million, eight hundred thousand, ninety-one".