821142 has 60 divisors (see below), whose sum is σ = 2184780. Its totient is φ = 222264.

The previous prime is 821131. The next prime is 821143. The reversal of 821142 is 241128.

821142 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a plaindrome in base 13 and base 15.

It is a nialpdrome in base 7.

It is a zygodrome in base 7 and base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821143) by changing a digit.

821142 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 43209 + ... + 43227.

It is an arithmetic number, because the mean of its divisors is an integer number (36413).

2⁸²¹¹⁴² is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 821142, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1092390).

821142 is an abundant number, since it is smaller than the sum of its proper divisors (1363638).

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

821142 is a wasteful number, since it uses less digits than its factorization.

821142 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55 (or 31 counting only the distinct ones).

The product of its digits is 128, while the sum is 18.

The square root of 821142 is about 906.1688584364. The cubic root of 821142 is about 93.6424473264.

The spelling of 821142 in words is "eight hundred twenty-one thousand, one hundred forty-two".