21043424032 has 12 divisors (see below), whose sum is σ = 41429241126. Its totient is φ = 10521712000.

The previous prime is 21043424029. The next prime is 21043424047. The reversal of 21043424032 is 23042434012.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 11749692816 + 9293731216 = 108396^2 + 96404^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21043423988 and 21043424006.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328803469 + ... + 328803532.

Almost surely, 2^21043424032 is an apocalyptic number.

It is an amenable number.

21043424032 is a deficient number, since it is larger than the sum of its proper divisors (20385817094).

21043424032 is an equidigital number, since it uses as much as digits as its factorization.

21043424032 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 657607011 (or 657607003 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 25.

Adding to 21043424032 its reverse (23042434012), we get a palindrome (44085858044).

The spelling of 21043424032 in words is "twenty-one billion, forty-three million, four hundred twenty-four thousand, thirty-two".