21843000 has 128 divisors (see below), whose sum is σ = 75816000. Its totient is φ = 5817600.

The previous prime is 21842999. The next prime is 21843043. The reversal of 21843000 is 34812.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 26596 + ... + 27404.

Almost surely, 2^21843000 is an apocalyptic number.

21843000 is a gapful number since it is divisible by the number (20) 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 21843000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37908000).

21843000 is an abundant number, since it is smaller than the sum of its proper divisors (53973000).

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

21843000 is a wasteful number, since it uses less digits than its factorization.

21843000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 839 (or 819 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 21843000 is about 4673.6495375670. The cubic root of 21843000 is about 279.5357954588.

Adding to 21843000 its reverse (34812), we get a palindrome (21877812).

It can be divided in two parts, 2184 and 3000, that added together give a square (5184 = 72²).

The spelling of 21843000 in words is "twenty-one million, eight hundred forty-three thousand".