199920685 has 4 divisors (see below), whose sum is σ = 239904828. Its totient is φ = 159936544.

The previous prime is 199920659. The next prime is 199920701. The reversal of 199920685 is 586029991.

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 93954249 + 105966436 = 9693^2 + 10294^2 .

It is a cyclic number.

It is not a de Polignac number, because 199920685 - 2⁹ = 199920173 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19992064 + ... + 19992073.

It is an arithmetic number, because the mean of its divisors is an integer number (59976207).

Almost surely, 2^199920685 is an apocalyptic number.

It is an amenable number.

199920685 is a deficient number, since it is larger than the sum of its proper divisors (39984143).

199920685 is an equidigital number, since it uses as much as digits as its factorization.

199920685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39984142.

The product of its (nonzero) digits is 349920, while the sum is 49.

The square root of 199920685 is about 14139.3311369386. The cubic root of 199920685 is about 584.7262312655.

The spelling of 199920685 in words is "one hundred ninety-nine million, nine hundred twenty thousand, six hundred eighty-five".