821118 has 16 divisors (see below), whose sum is σ = 1658880. Its totient is φ = 270936.

The previous prime is 821113. The next prime is 821131. The reversal of 821118 is 811128.

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 821094 and 821103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821113) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3 + ... + 1281.

It is an arithmetic number, because the mean of its divisors is an integer number (103680).

2⁸²¹¹¹⁸ is an apocalyptic number.

821118 is an abundant number, since it is smaller than the sum of its proper divisors (837762).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

821118 is a wasteful number, since it uses less digits than its factorization.

821118 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1391.

The product of its digits is 128, while the sum is 21.

The square root of 821118 is about 906.1556157747. The cubic root of 821118 is about 93.6415350032.

It can be divided in two parts, 821 and 118, that added together give a palindrome (939).

The spelling of 821118 in words is "eight hundred twenty-one thousand, one hundred eighteen".