205842 has 48 divisors (see below), whose sum is σ = 527040. Its totient is φ = 52416.

The previous prime is 205837. The next prime is 205847. The reversal of 205842 is 248502.

It is an interprime number because it is at equal distance from previous prime (205837) and next prime (205847).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 205842.

It is not an unprimeable number, because it can be changed into a prime (205847) by changing a digit.

205842 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7084 + ... + 7112.

It is an arithmetic number, because the mean of its divisors is an integer number (10980).

2²⁰⁵⁸⁴² is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 205842, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (263520).

205842 is an abundant number, since it is smaller than the sum of its proper divisors (321198).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

205842 is a wasteful number, since it uses less digits than its factorization.

205842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67 (or 54 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 21.

The square root of 205842 is about 453.6981375320. The cubic root of 205842 is about 59.0443026440.

It can be divided in two parts, 2058 and 42, that multiplied together give a square (86436 = 294²).

The spelling of 205842 in words is "two hundred five thousand, eight hundred forty-two".