199165261 has 2 divisors, whose sum is σ = 199165262. Its totient is φ = 199165260.

The previous prime is 199165259. The next prime is 199165321. The reversal of 199165261 is 162561991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 181575625 + 17589636 = 13475^2 + 4194^2 .

It is an emirp because it is prime and its reverse (162561991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 199165261 - 2¹ = 199165259 is a prime.

Together with 199165259, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199165231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99582630 + 99582631.

It is an arithmetic number, because the mean of its divisors is an integer number (99582631).

Almost surely, 2^199165261 is an apocalyptic number.

It is an amenable number.

199165261 is a deficient number, since it is larger than the sum of its proper divisors (1).

199165261 is an equidigital number, since it uses as much as digits as its factorization.

199165261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 29160, while the sum is 40.

The square root of 199165261 is about 14112.5922849064. The cubic root of 199165261 is about 583.9888158942.

The spelling of 199165261 in words is "one hundred ninety-nine million, one hundred sixty-five thousand, two hundred sixty-one".