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2845 = 5569
BaseRepresentation
bin101100011101
310220101
4230131
542340
621101
711203
oct5435
93811
102845
112157
121791
1313ab
141073
15c9a
hexb1d

2845 has 4 divisors (see below), whose sum is σ = 3420. Its totient is φ = 2272.

The previous prime is 2843. The next prime is 2851. The reversal of 2845 is 5482.

It can be divided in two parts, 284 and 5, that added together give a square (289 = 172).

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5482 = 22741.

It can be written as a sum of positive squares in 2 ways, for example, as 729 + 2116 = 27^2 + 46^2 .

It is a cyclic number.

It is not a de Polignac number, because 2845 - 21 = 2843 is a prime.

2845 is a lucky number.

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2843) 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 3 ways as a sum of consecutive naturals, for example, 280 + ... + 289.

It is an arithmetic number, because the mean of its divisors is an integer number (855).

22845 is an apocalyptic number.

It is an amenable number.

2845 is a deficient number, since it is larger than the sum of its proper divisors (575).

2845 is an equidigital number, since it uses as much as digits as its factorization.

2845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 574.

The product of its digits is 320, while the sum is 19.

The square root of 2845 is about 53.3385414124. The cubic root of 2845 is about 14.1697033091.

The spelling of 2845 in words is "two thousand, eight hundred forty-five".

Divisors: 1 5 569 2845