21573444032 has 84 divisors (see below), whose sum is σ = 49852502784. Its totient is φ = 9235860480.

The previous prime is 21573444017. The next prime is 21573444041. The reversal of 21573444032 is 23044437512.

It is a junction number, because it is equal to n+sod(n) for n = 21573443983 and 21573444001.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3437057 + ... + 3443327.

It is an arithmetic number, because the mean of its divisors is an integer number (593482176).

Almost surely, 2^21573444032 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 21573444032, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24926251392).

21573444032 is an abundant number, since it is smaller than the sum of its proper divisors (28279058752).

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

21573444032 is a wasteful number, since it uses less digits than its factorization.

21573444032 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7394 (or 7377 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 35.

The spelling of 21573444032 in words is "twenty-one billion, five hundred seventy-three million, four hundred forty-four thousand, thirty-two".