81528 has 32 divisors (see below), whose sum is σ = 211200. Its totient is φ = 26208.

The previous prime is 81527. The next prime is 81533. The reversal of 81528 is 82518.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a junction number, because it is equal to n+sod(n) for n = 81498 and 81507.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 81528.

It is not an unprimeable number, because it can be changed into a prime (81527) 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, 993 + ... + 1071.

It is an arithmetic number, because the mean of its divisors is an integer number (6600).

2⁸¹⁵²⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105600).

81528 is an abundant number, since it is smaller than the sum of its proper divisors (129672).

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

81528 is a wasteful number, since it uses less digits than its factorization.

81528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131 (or 127 counting only the distinct ones).

The product of its digits is 640, while the sum is 24.

The square root of 81528 is about 285.5310841222. The cubic root of 81528 is about 43.3612968753.

Subtracting 81528 from its reverse (82518), we obtain a triangular number (990 = T₄₄).

The spelling of 81528 in words is "eighty-one thousand, five hundred twenty-eight".