199309745 has 4 divisors (see below), whose sum is σ = 239171700. Its totient is φ = 159447792.

The previous prime is 199309741. The next prime is 199309769. The reversal of 199309745 is 547903991.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 145829776 + 53479969 = 12076^2 + 7313^2 .

It is a cyclic number.

It is not a de Polignac number, because 199309745 - 2² = 199309741 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 199309745.

It is not an unprimeable number, because it can be changed into a prime (199309741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19930970 + ... + 19930979.

It is an arithmetic number, because the mean of its divisors is an integer number (59792925).

Almost surely, 2^199309745 is an apocalyptic number.

It is an amenable number.

199309745 is a deficient number, since it is larger than the sum of its proper divisors (39861955).

199309745 is an equidigital number, since it uses as much as digits as its factorization.

199309745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39861954.

The product of its (nonzero) digits is 306180, while the sum is 47.

The square root of 199309745 is about 14117.7103313533. The cubic root of 199309745 is about 584.1299995594.

The spelling of 199309745 in words is "one hundred ninety-nine million, three hundred nine thousand, seven hundred forty-five".