21224240443 has 4 divisors (see below), whose sum is σ = 24256274800. Its totient is φ = 18192206088.

The previous prime is 21224240437. The next prime is 21224240447. The reversal of 21224240443 is 34404242212.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21224240443 - 2¹³ = 21224232251 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21224240447) 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, 1516017168 + ... + 1516017181.

It is an arithmetic number, because the mean of its divisors is an integer number (6064068700).

Almost surely, 2^21224240443 is an apocalyptic number.

21224240443 is a deficient number, since it is larger than the sum of its proper divisors (3032034357).

21224240443 is an equidigital number, since it uses as much as digits as its factorization.

21224240443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3032034356.

The product of its (nonzero) digits is 12288, while the sum is 28.

Adding to 21224240443 its reverse (34404242212), we get a palindrome (55628482655).

The spelling of 21224240443 in words is "twenty-one billion, two hundred twenty-four million, two hundred forty thousand, four hundred forty-three".