199680857 has 2 divisors, whose sum is σ = 199680858.
Its totient is φ = 199680856.
The previous prime is 199680851. The next prime is 199680881. The reversal of 199680857 is 758086991.
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 108076816 + 91604041 = 10396^2 + 9571^2
It is an emirp because it is prime and its reverse (758086991) is a distict prime.
It is a cyclic number.
It is not a de Polignac number, because 199680857 - 212 = 199676761 is a prime.
It is a Chen prime.
It is a junction number, because it is equal to n+sod(n) for n = 199680799 and 199680808.
It is not a weakly prime, because it can be changed into another prime (199680851) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (17) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99840428 + 99840429.
It is an arithmetic number, because the mean of its divisors is an integer number (99840429).
Almost surely, 2199680857 is an apocalyptic number.
It is an amenable number.
199680857 is a deficient number, since it is larger than the sum of its proper divisors (1).
199680857 is an equidigital number, since it uses as much as digits as its factorization.
199680857 is an odious number, because the sum of its binary digits is odd.
The product of its (nonzero) digits is 1088640, while the sum is 53.
The square root of 199680857 is about 14130.8477098863.
The cubic root of 199680857 is about 584.4923221104.
The spelling of 199680857 in words is "one hundred ninety-nine million, six hundred eighty thousand, eight hundred fifty-seven".