21833812 has 144 divisors (see below), whose sum is σ = 56306880. Its totient is φ = 7257600.

The previous prime is 21833807. The next prime is 21833813.

21833812 is nontrivially palindromic in base 10.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21833813) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 532512 + ... + 532552.

It is an arithmetic number, because the mean of its divisors is an integer number (391020).

Almost surely, 2^21833812 is an apocalyptic number.

21833812 is a gapful number since it is divisible by the number (22) 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 21833812, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28153440).

21833812 is an abundant number, since it is smaller than the sum of its proper divisors (34473068).

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

21833812 is a wasteful number, since it uses less digits than its factorization.

21833812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102 (or 93 counting only the distinct ones).

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

The square root of 21833812 is about 4672.6664764351. Note that the first 3 decimals coincide. The cubic root of 21833812 is about 279.4965954849.

It can be divided in two parts, 2183 and 3812, that added together give a palindrome (5995).

The spelling of 21833812 in words is "twenty-one million, eight hundred thirty-three thousand, eight hundred twelve".