204 has 12 divisors (see below), whose sum is σ = 504. Its totient is φ = 64.

The previous prime is 199. The next prime is 211. The reversal of 204 is 402.

204 is nontrivially palindromic in base 16.

204 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (12).

204 is an astonishing number since 204 = 4 + ... + 20.

It is a Harshad number since it is a multiple of its sum of digits (6).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a O'Halloran number.

204 is an undulating number in base 4.

204 is a nontrivial repdigit in base 16.

It is a plaindrome in base 9, base 13 and base 16.

It is a nialpdrome in base 6, base 7, base 15 and base 16.

It is a zygodrome in base 2 and base 16.

It is a junction number, because it is equal to *n*+sod(*n*) for *n* = 192 and 201.

It is an unprimeable number.

In principle, a polygon with 204 sides can be constructed with ruler and compass.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4 + ... + 20.

It is an arithmetic number, because the mean of its divisors is an integer number (42).

204 is the 8-th nonagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 204, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (252).

204 is an abundant number, since it is smaller than the sum of its proper divisors (300).

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

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

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

The sum of its prime factors is 24 (or 22 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 6.

The square root of 204 is about 14.2828568571. The cubic root of 204 is about 5.8867653169.

The spelling of 204 in words is "two hundred four", and is thus an aban number and an iban number.

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