12153566221 has 4 divisors (see below), whose sum is σ = 12174630172. Its totient is φ = 12132502272.

The previous prime is 12153566197. The next prime is 12153566233. The reversal of 12153566221 is 12266535121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12266535121 = 1487 ⋅8249183.

It can be written as a sum of positive squares in 2 ways, for example, as 10662834121 + 1490732100 = 103261^2 + 38610^2 .

It is a cyclic number.

It is not a de Polignac number, because 12153566221 - 2¹¹ = 12153564173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12153566921) 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, 10531110 + ... + 10532263.

It is an arithmetic number, because the mean of its divisors is an integer number (3043657543).

Almost surely, 2^12153566221 is an apocalyptic number.

It is an amenable number.

12153566221 is a deficient number, since it is larger than the sum of its proper divisors (21063951).

12153566221 is an equidigital number, since it uses as much as digits as its factorization.

12153566221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21063950.

The product of its digits is 21600, while the sum is 34.

The spelling of 12153566221 in words is "twelve billion, one hundred fifty-three million, five hundred sixty-six thousand, two hundred twenty-one".