12215530221 has 4 divisors (see below), whose sum is σ = 16287373632. Its totient is φ = 8143686812.

The previous prime is 12215530213. The next prime is 12215530231. The reversal of 12215530221 is 12203551221.

12215530221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12203551221 = 3 ⋅4067850407.

It is a cyclic number.

It is not a de Polignac number, because 12215530221 - 2³ = 12215530213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12215530191 and 12215530200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12215530211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2035921701 + ... + 2035921706.

It is an arithmetic number, because the mean of its divisors is an integer number (4071843408).

Almost surely, 2^12215530221 is an apocalyptic number.

It is an amenable number.

12215530221 is a deficient number, since it is larger than the sum of its proper divisors (4071843411).

12215530221 is an equidigital number, since it uses as much as digits as its factorization.

12215530221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4071843410.

The product of its (nonzero) digits is 1200, while the sum is 24.

The spelling of 12215530221 in words is "twelve billion, two hundred fifteen million, five hundred thirty thousand, two hundred twenty-one".