204161 has 2 divisors, whose sum is σ = 204162. Its totient is φ = 204160.

The previous prime is 204151. The next prime is 204163. The reversal of 204161 is 161402.

204161 = 319² + 320².

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 102400 + 101761 = 320^2 + 319^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-204161 is a prime.

Together with 204163, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (204163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102080 + 102081.

It is an arithmetic number, because the mean of its divisors is an integer number (102081).

2²⁰⁴¹⁶¹ is an apocalyptic number.

204161 is the 320-th centered square number.

It is an amenable number.

204161 is a deficient number, since it is larger than the sum of its proper divisors (1).

204161 is an equidigital number, since it uses as much as digits as its factorization.

204161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 204161 is about 451.8417864696. The cubic root of 204161 is about 58.8831355217.

Adding to 204161 its reverse (161402), we get a palindrome (365563).

The spelling of 204161 in words is "two hundred four thousand, one hundred sixty-one".