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BaseRepresentation
bin10000010111101
3102111102
42002331
5232011
6102445
733302
oct20275
912442
108381
11632a
124a25
133a79
1430a9
15273b
hex20bd

8381 has 6 divisors (see below), whose sum is σ = 9210. Its totient is φ = 7616.

The previous prime is 8377. The next prime is 8387. The reversal of 8381 is 1838.

8381 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 3481 + 4900 = 59^2 + 70^2 .

It is not a de Polignac number, because 8381 - 22 = 8377 is a prime.

It is a super-2 number, since 2×83812 = 140482322, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 275 + ... + 303.

It is an arithmetic number, because the mean of its divisors is an integer number (1535).

28381 is an apocalyptic number.

It is an amenable number.

8381 is a deficient number, since it is larger than the sum of its proper divisors (829).

8381 is a wasteful number, since it uses less digits than its factorization.

8381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63 (or 46 counting only the distinct ones).

The product of its digits is 192, while the sum is 20.

The square root of 8381 is about 91.5478017213. The cubic root of 8381 is about 20.3125889542.

The spelling of 8381 in words is "eight thousand, three hundred eighty-one".

Divisors: 1 17 29 289 493 8381