12520221 has 16 divisors (see below), whose sum is σ = 20083200. Its totient is φ = 6777648.

The previous prime is 12520219. The next prime is 12520237. The reversal of 12520221 is 12202521.

It is not a de Polignac number, because 12520221 - 2¹ = 12520219 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 12520221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12520201) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15291 + ... + 16088.

It is an arithmetic number, because the mean of its divisors is an integer number (1255200).

Almost surely, 2^12520221 is an apocalyptic number.

It is an amenable number.

12520221 is a deficient number, since it is larger than the sum of its proper divisors (7562979).

12520221 is a wasteful number, since it uses less digits than its factorization.

12520221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31408.

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 12520221 is about 3538.3924315994. The cubic root of 12520221 is about 232.2045176843.

Adding to 12520221 its reverse (12202521), we get a palindrome (24722742).

The spelling of 12520221 in words is "twelve million, five hundred twenty thousand, two hundred twenty-one".