81578 has 8 divisors (see below), whose sum is σ = 139872. Its totient is φ = 34956.

The previous prime is 81569. The next prime is 81611. The reversal of 81578 is 87518.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 81578.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2900 + ... + 2927.

It is an arithmetic number, because the mean of its divisors is an integer number (17484).

2⁸¹⁵⁷⁸ is an apocalyptic number.

81578 is a deficient number, since it is larger than the sum of its proper divisors (58294).

81578 is a wasteful number, since it uses less digits than its factorization.

81578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5836.

The product of its digits is 2240, while the sum is 29.

The square root of 81578 is about 285.6186268436. The cubic root of 81578 is about 43.3701593593.

It can be divided in two parts, 8157 and 8, that multiplied together give a palindrome (65256).

The spelling of 81578 in words is "eighty-one thousand, five hundred seventy-eight".