199841989 has 2 divisors, whose sum is σ = 199841990. Its totient is φ = 199841988.

The previous prime is 199841977. The next prime is 199842047. The reversal of 199841989 is 989148991.

It is an a-pointer prime, because the next prime (199842047) can be obtained adding 199841989 to its sum of digits (58).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 122102500 + 77739489 = 11050^2 + 8817^2 .

It is an emirp because it is prime and its reverse (989148991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 199841989 - 2²⁷ = 65624261 is a prime.

It is a super-2 number, since 2×199841989² = 79873641134952242, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199841189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99920994 + 99920995.

It is an arithmetic number, because the mean of its divisors is an integer number (99920995).

Almost surely, 2^199841989 is an apocalyptic number.

It is an amenable number.

199841989 is a deficient number, since it is larger than the sum of its proper divisors (1).

199841989 is an equidigital number, since it uses as much as digits as its factorization.

199841989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1679616, while the sum is 58.

The square root of 199841989 is about 14136.5479873978. The cubic root of 199841989 is about 584.6494980773.

The spelling of 199841989 in words is "one hundred ninety-nine million, eight hundred forty-one thousand, nine hundred eighty-nine".