81383 has 4 divisors (see below), whose sum is σ = 82320. Its totient is φ = 80448.

The previous prime is 81373. The next prime is 81401. The reversal of 81383 is 38318.

81383 is nontrivially palindromic in base 11.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81383 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81343) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 323 + ... + 516.

It is an arithmetic number, because the mean of its divisors is an integer number (20580).

2⁸¹³⁸³ is an apocalyptic number.

81383 is a deficient number, since it is larger than the sum of its proper divisors (937).

81383 is an equidigital number, since it uses as much as digits as its factorization.

81383 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 936.

The product of its digits is 576, while the sum is 23.

The square root of 81383 is about 285.2770583135. The cubic root of 81383 is about 43.3355751634.

Adding to 81383 its sum of digits (23), we get a triangular number (81406 = T₄₀₃).

It can be divided in two parts, 81 and 383, that added together give a palindrome (464).

The spelling of 81383 in words is "eighty-one thousand, three hundred eighty-three".