199685161 has 9 divisors (see below), whose sum is σ = 216426231. Its totient is φ = 184155192.

The previous prime is 199685159. The next prime is 199685183. The reversal of 199685161 is 161586991.

It is a happy number.

The square root of 199685161 is 14131.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 29539225 + 170145936 = 5435^2 + 13044^2 .

It is not a de Polignac number, because 199685161 - 2¹ = 199685159 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (199685131) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 183160 + ... + 184246.

It is an arithmetic number, because the mean of its divisors is an integer number (24047359).

Almost surely, 2^199685161 is an apocalyptic number.

199685161 is the 14131-st square number.

199685161 is the 7066-th centered octagonal number.

It is an amenable number.

199685161 is a deficient number, since it is larger than the sum of its proper divisors (16741070).

199685161 is an frugal number, since it uses more digits than its factorization.

199685161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2200 (or 1100 counting only the distinct ones).

The product of its digits is 116640, while the sum is 46.

The cubic root of 199685161 is about 584.4965215396.

The spelling of 199685161 in words is "one hundred ninety-nine million, six hundred eighty-five thousand, one hundred sixty-one".