12543332221 has 16 divisors (see below), whose sum is σ = 14560190208. Its totient is φ = 10583193600.

The previous prime is 12543332183. The next prime is 12543332273. The reversal of 12543332221 is 12223334521.

It is a happy number.

It is not a de Polignac number, because 12543332221 - 2⁷ = 12543332093 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12543332221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12543332281) 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, 298891 + ... + 338263.

It is an arithmetic number, because the mean of its divisors is an integer number (910011888).

Almost surely, 2^12543332221 is an apocalyptic number.

It is an amenable number.

12543332221 is a deficient number, since it is larger than the sum of its proper divisors (2016857987).

12543332221 is an equidigital number, since it uses as much as digits as its factorization.

12543332221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40092.

The product of its digits is 8640, while the sum is 28.

Adding to 12543332221 its reverse (12223334521), we get a palindrome (24766666742).

The spelling of 12543332221 in words is "twelve billion, five hundred forty-three million, three hundred thirty-two thousand, two hundred twenty-one".