21124321424 has 20 divisors (see below), whose sum is σ = 40942590444. Its totient is φ = 10558491648.

The previous prime is 21124321423. The next prime is 21124321501. The reversal of 21124321424 is 42412342112.

It can be written as a sum of positive squares in 2 ways, for example, as 2836627600 + 18287693824 = 53260^2 + 135232^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21124321393 and 21124321402.

It is not an unprimeable number, because it can be changed into a prime (21124321423) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 181517 + ... + 274220.

Almost surely, 2^21124321424 is an apocalyptic number.

It is an amenable number.

21124321424 is a deficient number, since it is larger than the sum of its proper divisors (19818269020).

21124321424 is a wasteful number, since it uses less digits than its factorization.

21124321424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 458642 (or 458636 counting only the distinct ones).

The product of its digits is 3072, while the sum is 26.

Adding to 21124321424 its reverse (42412342112), we get a palindrome (63536663536).

The spelling of 21124321424 in words is "twenty-one billion, one hundred twenty-four million, three hundred twenty-one thousand, four hundred twenty-four".