81120 has 72 divisors (see below), whose sum is σ = 276696. Its totient is φ = 19968.

The previous prime is 81119. The next prime is 81131. The reversal of 81120 is 2118.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 81096 and 81105.

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, 6234 + ... + 6246.

It is an arithmetic number, because the mean of its divisors is an integer number (3843).

2⁸¹¹²⁰ is an apocalyptic number.

81120 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 81120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138348).

81120 is an abundant number, since it is smaller than the sum of its proper divisors (195576).

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

81120 is a wasteful number, since it uses less digits than its factorization.

81120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44 (or 23 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 81120 is about 284.8157299027. The cubic root of 81120 is about 43.2888432268.

Adding to 81120 its reverse (2118), we get a palindrome (83238).

It can be divided in two parts, 8 and 1120, that added together give a triangular number (1128 = T₄₇).

The spelling of 81120 in words is "eighty-one thousand, one hundred twenty".