21224404441 has 8 divisors (see below), whose sum is σ = 21749802984. Its totient is φ = 20699374080.

The previous prime is 21224404403. The next prime is 21224404447. The reversal of 21224404441 is 14440442212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2333276416 + 18891128025 = 48304^2 + 137445^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21224404441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21224404447) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26541 + ... + 207733.

It is an arithmetic number, because the mean of its divisors is an integer number (2718725373).

Almost surely, 2^21224404441 is an apocalyptic number.

It is an amenable number.

21224404441 is a deficient number, since it is larger than the sum of its proper divisors (525398543).

21224404441 is a wasteful number, since it uses less digits than its factorization.

21224404441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 184091.

The product of its (nonzero) digits is 8192, while the sum is 28.

Adding to 21224404441 its reverse (14440442212), we get a palindrome (35664846653).

The spelling of 21224404441 in words is "twenty-one billion, two hundred twenty-four million, four hundred four thousand, four hundred forty-one".