849 has 4 divisors (see below), whose sum is σ = 1136. Its totient is φ = 564.

The previous prime is 839. The next prime is 853. The reversal of 849 is 948.

Subtracting from 849 its sum of digits (21), we obtain a palindrome (828).

Subtracting from 849 its product of digits (288), we obtain a triangular number (561 = T_{33}).

Subtracting 849 from its reverse (948), we obtain a palindrome (99).

849 = T_{9} + T_{10} + ... +
T_{17}.

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

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 849 - 2^{8} = 593 is a prime.

It is an Ulam number.

It is a d-powerful number, because it can be written as **8**^{3} + **4**^{4} + **9**^{2} .

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 5 and base 14.

It is not an unprimeable number, because it can be changed into a prime (809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 139 + ... + 144.

It is an arithmetic number, because the mean of its divisors is an integer number (284).

It is an amenable number.

849 is a deficient number, since it is larger than the sum of its proper divisors (287).

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

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

The sum of its prime factors is 286.

The product of its digits is 288, while the sum is 21.

The square root of 849 is about 29.1376045687. The cubic root of 849 is about 9.4689661367.

The spelling of 849 in words is "eight hundred forty-nine", and thus it is an aban number.

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