21321040444 has 48 divisors (see below), whose sum is σ = 41038534656. Its totient is φ = 9611993600.

The previous prime is 21321040423. The next prime is 21321040451. The reversal of 21321040444 is 44404012312.

It is a super-2 number, since 2×21321040444² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2963019 + ... + 2970205.

It is an arithmetic number, because the mean of its divisors is an integer number (854969472).

Almost surely, 2^21321040444 is an apocalyptic number.

It is an amenable number.

21321040444 is a deficient number, since it is larger than the sum of its proper divisors (19717494212).

21321040444 is a wasteful number, since it uses less digits than its factorization.

21321040444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7746 (or 7744 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 25.

Adding to 21321040444 its reverse (44404012312), we get a palindrome (65725052756).

The spelling of 21321040444 in words is "twenty-one billion, three hundred twenty-one million, forty thousand, four hundred forty-four".