205978 has 8 divisors (see below), whose sum is σ = 311220. Its totient is φ = 102240.

The previous prime is 205967. The next prime is 205981. The reversal of 205978 is 879502.

It can be written as a sum of positive squares in 2 ways, for example, as 154449 + 51529 = 393^2 + 227^2 .

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

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, 78 + ... + 646.

2²⁰⁵⁹⁷⁸ is an apocalyptic number.

205978 is a deficient number, since it is larger than the sum of its proper divisors (105242).

205978 is a wasteful number, since it uses less digits than its factorization.

205978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 752.

The product of its (nonzero) digits is 5040, while the sum is 31.

The square root of 205978 is about 453.8479921736. The cubic root of 205978 is about 59.0573033230.

The spelling of 205978 in words is "two hundred five thousand, nine hundred seventy-eight".