12715221 has 4 divisors (see below), whose sum is σ = 16953632. Its totient is φ = 8476812.

The previous prime is 12715211. The next prime is 12715249. The reversal of 12715221 is 12251721.

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: 12251721 = 3 ⋅4083907.

It is not a de Polignac number, because 12715221 - 2⁵ = 12715189 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12715211) 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, 2119201 + ... + 2119206.

It is an arithmetic number, because the mean of its divisors is an integer number (4238408).

Almost surely, 2^12715221 is an apocalyptic number.

It is an amenable number.

12715221 is a deficient number, since it is larger than the sum of its proper divisors (4238411).

12715221 is an equidigital number, since it uses as much as digits as its factorization.

12715221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4238410.

The product of its digits is 280, while the sum is 21.

The square root of 12715221 is about 3565.8408545531. The cubic root of 12715221 is about 233.4038260934.

Adding to 12715221 its reverse (12251721), we get a palindrome (24966942).

The spelling of 12715221 in words is "twelve million, seven hundred fifteen thousand, two hundred twenty-one".