204991849 has 2 divisors, whose sum is σ = 204991850. Its totient is φ = 204991848.

The previous prime is 204991837. The next prime is 204991859. The reversal of 204991849 is 948199402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 179560000 + 25431849 = 13400^2 + 5043^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-204991849 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 204991799 and 204991808.

It is not a weakly prime, because it can be changed into another prime (204991819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102495924 + 102495925.

It is an arithmetic number, because the mean of its divisors is an integer number (102495925).

Almost surely, 2^204991849 is an apocalyptic number.

It is an amenable number.

204991849 is a deficient number, since it is larger than the sum of its proper divisors (1).

204991849 is an equidigital number, since it uses as much as digits as its factorization.

204991849 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 186624, while the sum is 46.

The square root of 204991849 is about 14317.5364151798. The cubic root of 204991849 is about 589.6290390479.

The spelling of 204991849 in words is "two hundred four million, nine hundred ninety-one thousand, eight hundred forty-nine".