209199969 has 32 divisors (see below), whose sum is σ = 342768000. Its totient is φ = 125038080.

The previous prime is 209199919. The next prime is 209199983. The reversal of 209199969 is 969991902.

It is a happy number.

It is not a de Polignac number, because 209199969 - 2⁸ = 209199713 is a prime.

It is a super-2 number, since 2×209199969² = 87529254059201922, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (209199919) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16857 + ... + 26505.

It is an arithmetic number, because the mean of its divisors is an integer number (10711500).

Almost surely, 2^209199969 is an apocalyptic number.

It is an amenable number.

209199969 is a deficient number, since it is larger than the sum of its proper divisors (133568031).

209199969 is a wasteful number, since it uses less digits than its factorization.

209199969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9742 (or 9736 counting only the distinct ones).

The product of its (nonzero) digits is 708588, while the sum is 54.

The square root of 209199969 is about 14463.7467137668. The cubic root of 209199969 is about 593.6364217247.

The spelling of 209199969 in words is "two hundred nine million, one hundred ninety-nine thousand, nine hundred sixty-nine".