205579 has 6 divisors (see below), whose sum is σ = 226100. Its totient is φ = 186780.

The previous prime is 205559. The next prime is 205589. The reversal of 205579 is 975502.

It is not a de Polignac number, because 205579 - 2¹¹ = 203531 is a prime.

It is a Duffinian number.

205579 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (205519) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 729 + ... + 970.

2²⁰⁵⁵⁷⁹ is an apocalyptic number.

205579 is a deficient number, since it is larger than the sum of its proper divisors (20521).

205579 is a wasteful number, since it uses less digits than its factorization.

205579 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1721 (or 1710 counting only the distinct ones).

The product of its (nonzero) digits is 3150, while the sum is 28.

The square root of 205579 is about 453.4082046015. The cubic root of 205579 is about 59.0191453715.

It can be divided in two parts, 205 and 579, that added together give a square (784 = 28²).

The spelling of 205579 in words is "two hundred five thousand, five hundred seventy-nine".