199999649 has 2 divisors, whose sum is σ = 199999650. Its totient is φ = 199999648.

The previous prime is 199999609. The next prime is 199999661. The reversal of 199999649 is 946999991.

199999649 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 199713424 + 286225 = 14132^2 + 535^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-199999649 is a prime.

It is not a weakly prime, because it can be changed into another prime (199999609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99999824 + 99999825.

It is an arithmetic number, because the mean of its divisors is an integer number (99999825).

Almost surely, 2^199999649 is an apocalyptic number.

It is an amenable number.

199999649 is a deficient number, since it is larger than the sum of its proper divisors (1).

199999649 is an equidigital number, since it uses as much as digits as its factorization.

199999649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12754584, while the sum is 65.

The square root of 199999649 is about 14142.1232140015. The cubic root of 199999649 is about 584.8032055323.

The spelling of 199999649 in words is "one hundred ninety-nine million, nine hundred ninety-nine thousand, six hundred forty-nine".