81204 has 24 divisors (see below), whose sum is σ = 194208. Its totient is φ = 26400.

The previous prime is 81203. The next prime is 81223. The reversal of 81204 is 40218.

It is an Ulam number.

It is a plaindrome in base 9.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81203) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 754 + ... + 854.

It is an arithmetic number, because the mean of its divisors is an integer number (8092).

2⁸¹²⁰⁴ is an apocalyptic number.

It is an amenable number.

81204 is an abundant number, since it is smaller than the sum of its proper divisors (113004).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97104).

81204 is a wasteful number, since it uses less digits than its factorization.

81204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175 (or 173 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 81204 is about 284.9631555131. The cubic root of 81204 is about 43.3037799807.

The spelling of 81204 in words is "eighty-one thousand, two hundred four".