21243324321 has 48 divisors (see below), whose sum is σ = 33003210240. Its totient is φ = 13119160320.

The previous prime is 21243324307. The next prime is 21243324329. The reversal of 21243324321 is 12342334212.

21243324321 is a `hidden beast` number, since 2 + 1 + 2 + 4 + 332 + 4 + 321 = 666.

It is not a de Polignac number, because 21243324321 - 2³³ = 12653389729 is a prime.

It is a super-2 number, since 2×21243324321² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21243324329) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8352376 + ... + 8354918.

It is an arithmetic number, because the mean of its divisors is an integer number (687566880).

Almost surely, 2^21243324321 is an apocalyptic number.

It is an amenable number.

21243324321 is a deficient number, since it is larger than the sum of its proper divisors (11759885919).

21243324321 is a wasteful number, since it uses less digits than its factorization.

21243324321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3406 (or 3403 counting only the distinct ones).

The product of its digits is 6912, while the sum is 27.

Adding to 21243324321 its reverse (12342334212), we get a palindrome (33585658533).

The spelling of 21243324321 in words is "twenty-one billion, two hundred forty-three million, three hundred twenty-four thousand, three hundred twenty-one".