81360 has 60 divisors (see below), whose sum is σ = 275652. Its totient is φ = 21504.

The previous prime is 81359. The next prime is 81371. The reversal of 81360 is 6318.

It can be written as a sum of positive squares in 2 ways, for example, as 11664 + 69696 = 108^2 + 264^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 664 + ... + 776.

2⁸¹³⁶⁰ is an apocalyptic number.

81360 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (137826).

81360 is an abundant number, since it is smaller than the sum of its proper divisors (194292).

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

81360 is a wasteful number, since it uses less digits than its factorization.

81360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132 (or 123 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 81360 is about 285.2367437761. The cubic root of 81360 is about 43.3314923610.

81360 divided by its product of nonzero digits (144) gives a palindrome (565).

Adding to 81360 its reverse (6318), we get a palindrome (87678).

It can be divided in two parts, 81 and 360, that added together give a square (441 = 21²).

The spelling of 81360 in words is "eighty-one thousand, three hundred sixty".