21043032444 has 120 divisors (see below), whose sum is σ = 64055886048. Its totient is φ = 5898821760.

The previous prime is 21043032379. The next prime is 21043032457. The reversal of 21043032444 is 44423034012.

It is a happy number.

21043032444 is a `hidden beast` number, since 210 + 4 + 3 + 0 + 3 + 2 + 444 = 666.

It is a super-2 number, since 2×21043032444² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 32674 + ... + 207734.

Almost surely, 2^21043032444 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 21043032444, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32027943024).

21043032444 is an abundant number, since it is smaller than the sum of its proper divisors (43012853604).

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

21043032444 is a wasteful number, since it uses less digits than its factorization.

21043032444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175137 (or 175126 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 27.

Adding to 21043032444 its reverse (44423034012), we get a palindrome (65466066456).

The spelling of 21043032444 in words is "twenty-one billion, forty-three million, thirty-two thousand, four hundred forty-four".