199998749 has 2 divisors, whose sum is σ = 199998750. Its totient is φ = 199998748.

The previous prime is 199998713. The next prime is 199998751. The reversal of 199998749 is 947899991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 189062500 + 10936249 = 13750^2 + 3307^2 .

It is a cyclic number.

It is not a de Polignac number, because 199998749 - 2¹⁶ = 199933213 is a prime.

Together with 199998751, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199998049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99999374 + 99999375.

It is an arithmetic number, because the mean of its divisors is an integer number (99999375).

Almost surely, 2^199998749 is an apocalyptic number.

It is an amenable number.

199998749 is a deficient number, since it is larger than the sum of its proper divisors (1).

199998749 is an equidigital number, since it uses as much as digits as its factorization.

199998749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13226976, while the sum is 65.

The square root of 199998749 is about 14142.0913941326. The cubic root of 199998749 is about 584.8023283246.

The spelling of 199998749 in words is "one hundred ninety-nine million, nine hundred ninety-eight thousand, seven hundred forty-nine".