205901 has 4 divisors (see below), whose sum is σ = 207900. Its totient is φ = 203904.

The previous prime is 205883. The next prime is 205913. The reversal of 205901 is 109502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 109502 = 2 ⋅54751.

It can be written as a sum of positive squares in 2 ways, for example, as 121801 + 84100 = 349^2 + 290^2 .

It is a cyclic number.

It is not a de Polignac number, because 205901 - 2⁶ = 205837 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 205901.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 205901.

It is not an unprimeable number, because it can be changed into a prime (205951) 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, 836 + ... + 1053.

It is an arithmetic number, because the mean of its divisors is an integer number (51975).

2²⁰⁵⁹⁰¹ is an apocalyptic number.

It is an amenable number.

205901 is a deficient number, since it is larger than the sum of its proper divisors (1999).

205901 is a wasteful number, since it uses less digits than its factorization.

205901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1998.

The product of its (nonzero) digits is 90, while the sum is 17.

The square root of 205901 is about 453.7631540793. The cubic root of 205901 is about 59.0499433475.

The spelling of 205901 in words is "two hundred five thousand, nine hundred one".