12536221 has 4 divisors (see below), whose sum is σ = 12660444. Its totient is φ = 12412000.

The previous prime is 12536197. The next prime is 12536231. The reversal of 12536221 is 12263521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12263521 = 101 ⋅121421.

It can be written as a sum of positive squares in 2 ways, for example, as 9696996 + 2839225 = 3114^2 + 1685^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12536221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12536192 and 12536201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12536231) 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, 61960 + ... + 62161.

It is an arithmetic number, because the mean of its divisors is an integer number (3165111).

Almost surely, 2^12536221 is an apocalyptic number.

It is an amenable number.

12536221 is a deficient number, since it is larger than the sum of its proper divisors (124223).

12536221 is a wasteful number, since it uses less digits than its factorization.

12536221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124222.

The product of its digits is 720, while the sum is 22.

The square root of 12536221 is about 3540.6526234580. The cubic root of 12536221 is about 232.3033894955.

Adding to 12536221 its reverse (12263521), we get a palindrome (24799742).

The spelling of 12536221 in words is "twelve million, five hundred thirty-six thousand, two hundred twenty-one".