21444084 has 72 divisors (see below), whose sum is σ = 57788640. Its totient is φ = 6685632.

The previous prime is 21444083. The next prime is 21444091. The reversal of 21444084 is 48044412.

It is a happy number.

21444084 is a `hidden beast` number, since 214 + 440 + 8 + 4 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21444083) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 73042 + ... + 73334.

It is an arithmetic number, because the mean of its divisors is an integer number (802620).

Almost surely, 2^21444084 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 21444084, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28894320).

21444084 is an abundant number, since it is smaller than the sum of its proper divisors (36344556).

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

21444084 is a wasteful number, since it uses less digits than its factorization.

21444084 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 429 (or 424 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 27.

The square root of 21444084 is about 4630.7757449481. The cubic root of 21444084 is about 277.8236204992.

Adding to 21444084 its reverse (48044412), we get a palindrome (69488496).

It can be divided in two parts, 2144408 and 4, that added together give a palindrome (2144412).

The spelling of 21444084 in words is "twenty-one million, four hundred forty-four thousand, eighty-four".