21224220305 has 8 divisors (see below), whose sum is σ = 25472050344. Its totient is φ = 16977385600.

The previous prime is 21224220289. The next prime is 21224220361. The reversal of 21224220305 is 50302242212.

It can be written as a sum of positive squares in 4 ways, for example, as 4104067969 + 17120152336 = 64063^2 + 130844^2 .

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

It is not a de Polignac number, because 21224220305 - 2⁴ = 21224220289 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 201086 + ... + 287895.

It is an arithmetic number, because the mean of its divisors is an integer number (3184006293).

Almost surely, 2^21224220305 is an apocalyptic number.

It is an amenable number.

21224220305 is a deficient number, since it is larger than the sum of its proper divisors (4247830039).

21224220305 is an equidigital number, since it uses as much as digits as its factorization.

21224220305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 497667.

The product of its (nonzero) digits is 1920, while the sum is 23.

Adding to 21224220305 its reverse (50302242212), we get a palindrome (71526462517).

The spelling of 21224220305 in words is "twenty-one billion, two hundred twenty-four million, two hundred twenty thousand, three hundred five".