21001443321 has 16 divisors (see below), whose sum is σ = 28185615360. Its totient is φ = 13909268880.

The previous prime is 21001443311. The next prime is 21001443347. The reversal of 21001443321 is 12334410012.

It is not a de Polignac number, because 21001443321 - 2⁶ = 21001443257 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21001443311) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 552436 + ... + 589226.

It is an arithmetic number, because the mean of its divisors is an integer number (1761600960).

Almost surely, 2^21001443321 is an apocalyptic number.

It is an amenable number.

21001443321 is a deficient number, since it is larger than the sum of its proper divisors (7184172039).

21001443321 is a wasteful number, since it uses less digits than its factorization.

21001443321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38036.

The product of its (nonzero) digits is 576, while the sum is 21.

Adding to 21001443321 its reverse (12334410012), we get a palindrome (33335853333).

The spelling of 21001443321 in words is "twenty-one billion, one million, four hundred forty-three thousand, three hundred twenty-one".