205317947 has 2 divisors, whose sum is σ = 205317948. Its totient is φ = 205317946.

The previous prime is 205317923. The next prime is 205317997. The reversal of 205317947 is 749713502.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 205317947 - 2⁸ = 205317691 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 205317947.

It is not a weakly prime, because it can be changed into another prime (205317997) 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, 102658973 + 102658974.

It is an arithmetic number, because the mean of its divisors is an integer number (102658974).

Almost surely, 2^205317947 is an apocalyptic number.

205317947 is a deficient number, since it is larger than the sum of its proper divisors (1).

205317947 is an equidigital number, since it uses as much as digits as its factorization.

205317947 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 52920, while the sum is 38.

The square root of 205317947 is about 14328.9199523202. The cubic root of 205317947 is about 589.9415311206.

The spelling of 205317947 in words is "two hundred five million, three hundred seventeen thousand, nine hundred forty-seven".