205715971 has 4 divisors (see below), whose sum is σ = 208534072. Its totient is φ = 202897872.

The previous prime is 205715947. The next prime is 205715987. The reversal of 205715971 is 179517502.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 205715971 - 2⁹ = 205715459 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 205715971.

It is not an unprimeable number, because it can be changed into a prime (205715941) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1408941 + ... + 1409086.

It is an arithmetic number, because the mean of its divisors is an integer number (52133518).

Almost surely, 2^205715971 is an apocalyptic number.

205715971 is a deficient number, since it is larger than the sum of its proper divisors (2818101).

205715971 is an equidigital number, since it uses as much as digits as its factorization.

205715971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2818100.

The product of its (nonzero) digits is 22050, while the sum is 37.

The square root of 205715971 is about 14342.8020623587. The cubic root of 205715971 is about 590.3225001199.

The spelling of 205715971 in words is "two hundred five million, seven hundred fifteen thousand, nine hundred seventy-one".