205772009 has 2 divisors, whose sum is σ = 205772010. Its totient is φ = 205772008.

The previous prime is 205771967. The next prime is 205772027. The reversal of 205772009 is 900277502.

205772009 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., 117787609 + 87984400 = 10853^2 + 9380^2 .

It is a cyclic number.

It is not a de Polignac number, because 205772009 - 2²⁰ = 204723433 is a prime.

It is not a weakly prime, because it can be changed into another prime (205777009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102886004 + 102886005.

It is an arithmetic number, because the mean of its divisors is an integer number (102886005).

Almost surely, 2^205772009 is an apocalyptic number.

It is an amenable number.

205772009 is a deficient number, since it is larger than the sum of its proper divisors (1).

205772009 is an equidigital number, since it uses as much as digits as its factorization.

205772009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8820, while the sum is 32.

The square root of 205772009 is about 14344.7554527779. The cubic root of 205772009 is about 590.3760974639.

The spelling of 205772009 in words is "two hundred five million, seven hundred seventy-two thousand, nine".