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8005 = 51601
BaseRepresentation
bin1111101000101
3101222111
41331011
5224010
6101021
732224
oct17505
911874
108005
116018
124771
13384a
142cbb
15258a
hex1f45

8005 has 4 divisors (see below), whose sum is σ = 9612. Its totient is φ = 6400.

The previous prime is 7993. The next prime is 8009. The reversal of 8005 is 5008.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6241 + 1764 = 79^2 + 42^2 .

It is not a de Polignac number, because 8005 - 27 = 7877 is a prime.

It is a Smith number, since the sum of its digits (13) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

8005 is a lucky number.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8009) 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, 796 + ... + 805.

It is an arithmetic number, because the mean of its divisors is an integer number (2403).

28005 is an apocalyptic number.

It is an amenable number.

8005 is a deficient number, since it is larger than the sum of its proper divisors (1607).

8005 is a wasteful number, since it uses less digits than its factorization.

8005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1606.

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 8005 is about 89.4706655838. The cubic root of 8005 is about 20.0041657989.

The spelling of 8005 in words is "eight thousand, five".

Divisors: 1 5 1601 8005