81330 has 16 divisors (see below), whose sum is σ = 195264. Its totient is φ = 21680.

The previous prime is 81307. The next prime is 81331. The reversal of 81330 is 3318.

81330 = T₈₀ + T₈₁ + ... + T₉₉.

It is a super-2 number, since 2×81330² = 13229137800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is not an unprimeable number, because it can be changed into a prime (81331) 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, 1326 + ... + 1385.

It is an arithmetic number, because the mean of its divisors is an integer number (12204).

2⁸¹³³⁰ is an apocalyptic number.

81330 is an abundant number, since it is smaller than the sum of its proper divisors (113934).

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 (97632).

81330 is a wasteful number, since it uses less digits than its factorization.

81330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2721.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 81330 is about 285.1841510323. The cubic root of 81330 is about 43.3261658099.

Adding to 81330 its reverse (3318), we get a palindrome (84648).

The spelling of 81330 in words is "eighty-one thousand, three hundred thirty".