205121143 has 2 divisors, whose sum is σ = 205121144. Its totient is φ = 205121142.

The previous prime is 205121117. The next prime is 205121149. The reversal of 205121143 is 341121502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 205121143 - 2⁹ = 205120631 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 205121143.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205121149) 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, 102560571 + 102560572.

It is an arithmetic number, because the mean of its divisors is an integer number (102560572).

Almost surely, 2^205121143 is an apocalyptic number.

205121143 is a deficient number, since it is larger than the sum of its proper divisors (1).

205121143 is an equidigital number, since it uses as much as digits as its factorization.

205121143 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 205121143 is about 14322.0509355329. The cubic root of 205121143 is about 589.7529780810.

Adding to 205121143 its reverse (341121502), we get a palindrome (546242645).

The spelling of 205121143 in words is "two hundred five million, one hundred twenty-one thousand, one hundred forty-three".