823861 has 4 divisors (see below), whose sum is σ = 852300. Its totient is φ = 795424.

The previous prime is 823843. The next prime is 823877. The reversal of 823861 is 168328.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 481636 + 342225 = 694^2 + 585^2 .

It is a cyclic number.

It is not a de Polignac number, because 823861 - 2⁵ = 823829 is a prime.

It is a Duffinian number.

823861 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (823831) 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, 14176 + ... + 14233.

It is an arithmetic number, because the mean of its divisors is an integer number (213075).

2⁸²³⁸⁶¹ is an apocalyptic number.

It is an amenable number.

823861 is a deficient number, since it is larger than the sum of its proper divisors (28439).

823861 is a wasteful number, since it uses less digits than its factorization.

823861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28438.

The product of its digits is 2304, while the sum is 28.

The square root of 823861 is about 907.6678908059. The cubic root of 823861 is about 93.7456910612.

The spelling of 823861 in words is "eight hundred twenty-three thousand, eight hundred sixty-one".