204978 has 16 divisors (see below), whose sum is σ = 414720. Its totient is φ = 67536.

The previous prime is 204973. The next prime is 204979. The reversal of 204978 is 879402.

It is not an unprimeable number, because it can be changed into a prime (204973) by changing a digit.

204978 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 628 + ... + 896.

It is an arithmetic number, because the mean of its divisors is an integer number (25920).

2²⁰⁴⁹⁷⁸ is an apocalyptic number.

204978 is an abundant number, since it is smaller than the sum of its proper divisors (209742).

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

204978 is a wasteful number, since it uses less digits than its factorization.

204978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 401.

The product of its (nonzero) digits is 4032, while the sum is 30.

The square root of 204978 is about 452.7449613193. The cubic root of 204978 is about 58.9615760542.

The spelling of 204978 in words is "two hundred four thousand, nine hundred seventy-eight".