205409489 has 2 divisors, whose sum is σ = 205409490. Its totient is φ = 205409488.

The previous prime is 205409429. The next prime is 205409531. The reversal of 205409489 is 984904502.

205409489 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 112190464 + 93219025 = 10592^2 + 9655^2 .

It is a cyclic number.

It is not a de Polignac number, because 205409489 - 2¹² = 205405393 is a prime.

It is a super-2 number, since 2×205409489² = 84386116342482242, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (205409429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102704744 + 102704745.

It is an arithmetic number, because the mean of its divisors is an integer number (102704745).

Almost surely, 2^205409489 is an apocalyptic number.

It is an amenable number.

205409489 is a deficient number, since it is larger than the sum of its proper divisors (1).

205409489 is an equidigital number, since it uses as much as digits as its factorization.

205409489 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 103680, while the sum is 41.

The square root of 205409489 is about 14332.1139054921. The cubic root of 205409489 is about 590.0291941888.

The spelling of 205409489 in words is "two hundred five million, four hundred nine thousand, four hundred eighty-nine".