861822 has 48 divisors (see below), whose sum is σ = 2096640. Its totient is φ = 254016.

The previous prime is 861803. The next prime is 861823. The reversal of 861822 is 228168.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861823) by changing a digit.

861822 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 23 ways as a sum of consecutive naturals, for example, 6723 + ... + 6849.

It is an arithmetic number, because the mean of its divisors is an integer number (43680).

2⁸⁶¹⁸²² is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 861822, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1048320).

861822 is an abundant number, since it is smaller than the sum of its proper divisors (1234818).

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

861822 is a wasteful number, since it uses less digits than its factorization.

861822 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177 (or 174 counting only the distinct ones).

The product of its digits is 1536, while the sum is 27.

The square root of 861822 is about 928.3436863576. The cubic root of 861822 is about 95.1639643054.

The spelling of 861822 in words is "eight hundred sixty-one thousand, eight hundred twenty-two".