21243324547 has 16 divisors (see below), whose sum is σ = 23071708800. Its totient is φ = 19493040960.

The previous prime is 21243324503. The next prime is 21243324551. The reversal of 21243324547 is 74542334212.

It is a cyclic number.

It is not a de Polignac number, because 21243324547 - 2¹⁵ = 21243291779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21243322547) 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, 10188 + ... + 206374.

It is an arithmetic number, because the mean of its divisors is an integer number (1441981800).

Almost surely, 2^21243324547 is an apocalyptic number.

21243324547 is a deficient number, since it is larger than the sum of its proper divisors (1828384253).

21243324547 is a wasteful number, since it uses less digits than its factorization.

21243324547 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196386.

The product of its digits is 161280, while the sum is 37.

Adding to 21243324547 its reverse (74542334212), we get a palindrome (95785658759).

The spelling of 21243324547 in words is "twenty-one billion, two hundred forty-three million, three hundred twenty-four thousand, five hundred forty-seven".