821128 has 64 divisors (see below), whose sum is σ = 2027520. Its totient is φ = 302400.

The previous prime is 821113. The next prime is 821131.

821128 is nontrivially palindromic in base 10.

It is a hoax number, since the sum of its digits (22) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a nude number because it is divisible by every one of its digits.

It is a plaindrome in base 13 and base 15.

It is a zygodrome in base 13.

It is a junction number, because it is equal to n+sod(n) for n = 821099 and 821108.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19075 + ... + 19117.

It is an arithmetic number, because the mean of its divisors is an integer number (31680).

2⁸²¹¹²⁸ is an apocalyptic number.

821128 is a gapful number since it is divisible by the number (88) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 821128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1013760).

821128 is an abundant number, since it is smaller than the sum of its proper divisors (1206392).

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

821128 is a wasteful number, since it uses less digits than its factorization.

821128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98 (or 94 counting only the distinct ones).

The product of its digits is 256, while the sum is 22.

The square root of 821128 is about 906.1611335739. The cubic root of 821128 is about 93.6419151400.

It can be divided in two parts, 821 and 128, that added together give a palindrome (949).

The spelling of 821128 in words is "eight hundred twenty-one thousand, one hundred twenty-eight".