12204420521 has 4 divisors (see below), whose sum is σ = 12204815700. Its totient is φ = 12204025344.

The previous prime is 12204420497. The next prime is 12204420541. The reversal of 12204420521 is 12502440221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12502440221 = 3673 ⋅3403877.

It can be written as a sum of positive squares in 2 ways, for example, as 9238093225 + 2966327296 = 96115^2 + 54464^2 .

It is a cyclic number.

It is not a de Polignac number, because 12204420521 - 2¹⁰ = 12204419497 is a prime.

It is a super-2 number, since 2×12204420521² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12204420541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 146936 + ... + 214473.

It is an arithmetic number, because the mean of its divisors is an integer number (3051203925).

Almost surely, 2^12204420521 is an apocalyptic number.

It is an amenable number.

12204420521 is a deficient number, since it is larger than the sum of its proper divisors (395179).

12204420521 is an equidigital number, since it uses as much as digits as its factorization.

12204420521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 395178.

The product of its (nonzero) digits is 1280, while the sum is 23.

Adding to 12204420521 its reverse (12502440221), we get a palindrome (24706860742).

The spelling of 12204420521 in words is "twelve billion, two hundred four million, four hundred twenty thousand, five hundred twenty-one".