205109969 has 2 divisors, whose sum is σ = 205109970. Its totient is φ = 205109968.

The previous prime is 205109963. The next prime is 205110041. The reversal of 205109969 is 969901502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 171295744 + 33814225 = 13088^2 + 5815^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-205109969 is a prime.

It is a super-2 number, since 2×205109969² = 84140198766361922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (205109963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102554984 + 102554985.

It is an arithmetic number, because the mean of its divisors is an integer number (102554985).

Almost surely, 2^205109969 is an apocalyptic number.

It is an amenable number.

205109969 is a deficient number, since it is larger than the sum of its proper divisors (1).

205109969 is an equidigital number, since it uses as much as digits as its factorization.

205109969 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 43740, while the sum is 41.

The square root of 205109969 is about 14321.6608324593. The cubic root of 205109969 is about 589.7422689307.

The spelling of 205109969 in words is "two hundred five million, one hundred nine thousand, nine hundred sixty-nine".