199965851 has 2 divisors, whose sum is σ = 199965852. Its totient is φ = 199965850.

The previous prime is 199965811. The next prime is 199965853. The reversal of 199965851 is 158569991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 199965851 - 2¹⁴ = 199949467 is a prime.

Together with 199965853, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 199965793 and 199965802.

It is not a weakly prime, because it can be changed into another prime (199965853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99982925 + 99982926.

It is an arithmetic number, because the mean of its divisors is an integer number (99982926).

Almost surely, 2^199965851 is an apocalyptic number.

199965851 is a deficient number, since it is larger than the sum of its proper divisors (1).

199965851 is an equidigital number, since it uses as much as digits as its factorization.

199965851 is an evil number, because the sum of its binary digits is even.

The product of its digits is 874800, while the sum is 53.

The square root of 199965851 is about 14140.9282227158. The cubic root of 199965851 is about 584.7702616541.

The spelling of 199965851 in words is "one hundred ninety-nine million, nine hundred sixty-five thousand, eight hundred fifty-one".