21331443124 has 48 divisors (see below), whose sum is σ = 40441040640. Its totient is φ = 9806699520.

The previous prime is 21331443121. The next prime is 21331443143. The reversal of 21331443124 is 42134413312.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21331443092 and 21331443101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21331443121) 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, 1819072 + ... + 1830760.

It is an arithmetic number, because the mean of its divisors is an integer number (842521680).

Almost surely, 2^21331443124 is an apocalyptic number.

It is an amenable number.

21331443124 is a deficient number, since it is larger than the sum of its proper divisors (19109597516).

21331443124 is a wasteful number, since it uses less digits than its factorization.

21331443124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12328 (or 12326 counting only the distinct ones).

The product of its digits is 6912, while the sum is 28.

Adding to 21331443124 its reverse (42134413312), we get a palindrome (63465856436).

The spelling of 21331443124 in words is "twenty-one billion, three hundred thirty-one million, four hundred forty-three thousand, one hundred twenty-four".