205642 has 8 divisors (see below), whose sum is σ = 310500. Its totient is φ = 102144.

The previous prime is 205633. The next prime is 205651. The reversal of 205642 is 246502.

It is an interprime number because it is at equal distance from previous prime (205633) and next prime (205651).

It can be written as a sum of positive squares in 2 ways, for example, as 185761 + 19881 = 431^2 + 141^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 234 + ... + 682.

2²⁰⁵⁶⁴² is an apocalyptic number.

205642 is a deficient number, since it is larger than the sum of its proper divisors (104858).

205642 is a wasteful number, since it uses less digits than its factorization.

205642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 680.

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 205642 is about 453.4776730998. The cubic root of 205642 is about 59.0251735916.

The spelling of 205642 in words is "two hundred five thousand, six hundred forty-two".