81304 has 8 divisors (see below), whose sum is σ = 152460. Its totient is φ = 40648.

The previous prime is 81299. The next prime is 81307. The reversal of 81304 is 40318.

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×81304² = 13220680832, which contains 22 as substring.

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 (81307) by changing a digit.

81304 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5074 + ... + 5089.

2⁸¹³⁰⁴ is an apocalyptic number.

It is an amenable number.

81304 is a deficient number, since it is larger than the sum of its proper divisors (71156).

81304 is a wasteful number, since it uses less digits than its factorization.

81304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10169 (or 10165 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 81304 is about 285.1385628076. The cubic root of 81304 is about 43.3215484060.

The spelling of 81304 in words is "eighty-one thousand, three hundred four".