81532 has 24 divisors (see below), whose sum is σ = 166320. Its totient is φ = 34560.

The previous prime is 81527. The next prime is 81533. The reversal of 81532 is 23518.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81533) by changing a digit.

81532 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 694 + ... + 802.

It is an arithmetic number, because the mean of its divisors is an integer number (6930).

2⁸¹⁵³² is an apocalyptic number.

It is an amenable number.

81532 is an abundant number, since it is smaller than the sum of its proper divisors (84788).

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 (83160).

81532 is a wasteful number, since it uses less digits than its factorization.

81532 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141 (or 139 counting only the distinct ones).

The product of its digits is 240, while the sum is 19.

The square root of 81532 is about 285.5380885276. The cubic root of 81532 is about 43.3620060073.

It can be divided in two parts, 8 and 1532, that added together give a triangular number (1540 = T₅₅).

The spelling of 81532 in words is "eighty-one thousand, five hundred thirty-two".