81588 has 24 divisors (see below), whose sum is σ = 205408. Its totient is φ = 25056.

The previous prime is 81569. The next prime is 81611. The reversal of 81588 is 88518.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

81588 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 106 + ... + 417.

2⁸¹⁵⁸⁸ is an apocalyptic number.

It is an amenable number.

81588 is an abundant number, since it is smaller than the sum of its proper divisors (123820).

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 (102704).

81588 is a wasteful number, since it uses less digits than its factorization.

81588 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 543 (or 541 counting only the distinct ones).

The product of its digits is 2560, while the sum is 30.

The square root of 81588 is about 285.6361321682. The cubic root of 81588 is about 43.3719314215.

Adding to 81588 its sum of digits (30), we get a palindrome (81618).

Adding to 81588 its product of digits (2560), we get a palindrome (84148).

It can be divided in two parts, 815 and 88, that added together give a triangular number (903 = T₄₂).

The spelling of 81588 in words is "eighty-one thousand, five hundred eighty-eight".