199649851 has 2 divisors, whose sum is σ = 199649852. Its totient is φ = 199649850.

The previous prime is 199649837. The next prime is 199649897. The reversal of 199649851 is 158946991.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 199649851 - 2¹⁷ = 199518779 is a prime.

It is not a weakly prime, because it can be changed into another prime (199641851) 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, 99824925 + 99824926.

It is an arithmetic number, because the mean of its divisors is an integer number (99824926).

Almost surely, 2^199649851 is an apocalyptic number.

199649851 is a deficient number, since it is larger than the sum of its proper divisors (1).

199649851 is an equidigital number, since it uses as much as digits as its factorization.

199649851 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 699840, while the sum is 52.

The square root of 199649851 is about 14129.7505639696. The cubic root of 199649851 is about 584.4620676545.

The spelling of 199649851 in words is "one hundred ninety-nine million, six hundred forty-nine thousand, eight hundred fifty-one".