21441984 has 56 divisors (see below), whose sum is σ = 57137808. Its totient is φ = 7096320.

The previous prime is 21441967. The next prime is 21441989. The reversal of 21441984 is 48914412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21441989) 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 7 ways as a sum of consecutive naturals, for example, 34444 + ... + 35060.

It is an arithmetic number, because the mean of its divisors is an integer number (1020318).

Almost surely, 2^21441984 is an apocalyptic number.

21441984 is a gapful number since it is divisible by the number (24) 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 21441984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28568904).

21441984 is an abundant number, since it is smaller than the sum of its proper divisors (35695824).

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

21441984 is a wasteful number, since it uses less digits than its factorization.

21441984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 813 (or 803 counting only the distinct ones).

The product of its digits is 9216, while the sum is 33.

The square root of 21441984 is about 4630.5489955296. The cubic root of 21441984 is about 277.8145511967.

The spelling of 21441984 in words is "twenty-one million, four hundred forty-one thousand, nine hundred eighty-four".