199180081 has 2 divisors, whose sum is σ = 199180082.
Its totient is φ = 199180080.
The previous prime is 199180049. The next prime is 199180087. The reversal of 199180081 is 180081991.
It is a happy number.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 194853681 + 4326400 = 13959^2 + 2080^2
It is an emirp because it is prime and its reverse (180081991) is a distict prime.
It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 180081661 and 166180081.
It is a cyclic number.
It is not a de Polignac number, because 199180081 - 25 = 199180049 is a prime.
It is a super-2 number, since 2×1991800812 = 79345409334333122, which contains 22 as substring.
It is a Chen prime.
It is a self number, because there is not a number n which added to its sum of digits gives 199180081.
It is not a weakly prime, because it can be changed into another prime (199180087) 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 as a sum of consecutive naturals, namely, 99590040 + 99590041.
It is an arithmetic number, because the mean of its divisors is an integer number (99590041).
Almost surely, 2199180081 is an apocalyptic number.
It is an amenable number.
199180081 is a deficient number, since it is larger than the sum of its proper divisors (1).
199180081 is an equidigital number, since it uses as much as digits as its factorization.
199180081 is an odious number, because the sum of its binary digits is odd.
The product of its (nonzero) digits is 5184, while the sum is 37.
The square root of 199180081 is about 14113.1173381362.
The cubic root of 199180081 is about 584.0033005146.
The spelling of 199180081 in words is "one hundred ninety-nine million, one hundred eighty thousand, eighty-one".