81385 has 8 divisors (see below), whose sum is σ = 100296. Its totient is φ = 63360.

The previous prime is 81373. The next prime is 81401. The reversal of 81385 is 58318.

It can be written as a sum of positive squares in 4 ways, for example, as 1296 + 80089 = 36^2 + 283^2 .

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

It is not a de Polignac number, because 81385 - 2⁵ = 81353 is a prime.

It is a Duffinian number.

It is a plaindrome in base 9.

It is an unprimeable 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, 7 + ... + 403.

It is an arithmetic number, because the mean of its divisors is an integer number (12537).

2⁸¹³⁸⁵ is an apocalyptic number.

It is an amenable number.

81385 is a deficient number, since it is larger than the sum of its proper divisors (18911).

81385 is a wasteful number, since it uses less digits than its factorization.

81385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 443.

The product of its digits is 960, while the sum is 25.

The square root of 81385 is about 285.2805636562. The cubic root of 81385 is about 43.3359301534.

It can be divided in two parts, 813 and 85, that added together give a palindrome (898).

The spelling of 81385 in words is "eighty-one thousand, three hundred eighty-five".