21812832 has 144 divisors (see below), whose sum is σ = 67223520. Its totient is φ = 6690816.

The previous prime is 21812827. The next prime is 21812837. The reversal of 21812832 is 23821812.

It is an interprime number because it is at equal distance from previous prime (21812827) and next prime (21812837).

It is a tau number, because it is divible by the number of its divisors (144).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21812796 and 21812805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21812837) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 245044 + ... + 245132.

It is an arithmetic number, because the mean of its divisors is an integer number (466830).

Almost surely, 2^21812832 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21812832, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33611760).

21812832 is an abundant number, since it is smaller than the sum of its proper divisors (45410688).

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

21812832 is a wasteful number, since it uses less digits than its factorization.

21812832 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165 (or 154 counting only the distinct ones).

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

The square root of 21812832 is about 4670.4209660372. The cubic root of 21812832 is about 279.4070445053.

The spelling of 21812832 in words is "twenty-one million, eight hundred twelve thousand, eight hundred thirty-two".