849821 has 4 divisors (see below), whose sum is σ = 971232. Its totient is φ = 728412.

The previous prime is 849773. The next prime is 849829. The reversal of 849821 is 128948.

It is a happy number.

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 a cyclic number.

It is not a de Polignac number, because 849821 - 2¹⁰ = 848797 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 (849829) 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, 60695 + ... + 60708.

It is an arithmetic number, because the mean of its divisors is an integer number (242808).

2⁸⁴⁹⁸²¹ is an apocalyptic number.

It is an amenable number.

849821 is a deficient number, since it is larger than the sum of its proper divisors (121411).

849821 is a wasteful number, since it uses less digits than its factorization.

849821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121410.

The product of its digits is 4608, while the sum is 32.

The square root of 849821 is about 921.8573642381. The cubic root of 849821 is about 94.7201738002.

The spelling of 849821 in words is "eight hundred forty-nine thousand, eight hundred twenty-one".