205612171 has 4 divisors (see below), whose sum is σ = 210627144. Its totient is φ = 200597200.

The previous prime is 205612139. The next prime is 205612177. The reversal of 205612171 is 171216502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 171216502 = 2 ⋅85608251.

It is a cyclic number.

It is not a de Polignac number, because 205612171 - 2⁵ = 205612139 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205612177) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2507425 + ... + 2507506.

It is an arithmetic number, because the mean of its divisors is an integer number (52656786).

Almost surely, 2^205612171 is an apocalyptic number.

205612171 is a deficient number, since it is larger than the sum of its proper divisors (5014973).

205612171 is an equidigital number, since it uses as much as digits as its factorization.

205612171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5014972.

The product of its (nonzero) digits is 840, while the sum is 25.

The square root of 205612171 is about 14339.1830659909. The cubic root of 205612171 is about 590.2231952641.

Adding to 205612171 its reverse (171216502), we get a palindrome (376828673).

The spelling of 205612171 in words is "two hundred five million, six hundred twelve thousand, one hundred seventy-one".