205715947 has 2 divisors, whose sum is σ = 205715948. Its totient is φ = 205715946.

The previous prime is 205715941. The next prime is 205715987. The reversal of 205715947 is 749517502.

It is an a-pointer prime, because the next prime (205715987) can be obtained adding 205715947 to its sum of digits (40).

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-205715947 is a prime.

It is not a weakly prime, because it can be changed into another prime (205715941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102857973 + 102857974.

It is an arithmetic number, because the mean of its divisors is an integer number (102857974).

Almost surely, 2^205715947 is an apocalyptic number.

205715947 is a deficient number, since it is larger than the sum of its proper divisors (1).

205715947 is an equidigital number, since it uses as much as digits as its factorization.

205715947 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 88200, while the sum is 40.

The square root of 205715947 is about 14342.8012257020. The cubic root of 205715947 is about 590.3224771631.

The spelling of 205715947 in words is "two hundred five million, seven hundred fifteen thousand, nine hundred forty-seven".