12690221 has 4 divisors (see below), whose sum is σ = 12790272. Its totient is φ = 12590172.

The previous prime is 12690199. The next prime is 12690259. The reversal of 12690221 is 12209621.

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.

It is a cyclic number.

It is not a de Polignac number, because 12690221 - 2¹⁸ = 12428077 is a prime.

It is a super-3 number, since 3×12690221³ (a number of 22 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12690281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49835 + ... + 50088.

It is an arithmetic number, because the mean of its divisors is an integer number (3197568).

Almost surely, 2^12690221 is an apocalyptic number.

It is an amenable number.

12690221 is a deficient number, since it is larger than the sum of its proper divisors (100051).

12690221 is an equidigital number, since it uses as much as digits as its factorization.

12690221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100050.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 12690221 is about 3562.3336452387. Note that the first 3 decimals coincide. The cubic root of 12690221 is about 233.2507569476.

Adding to 12690221 its reverse (12209621), we get a palindrome (24899842).

The spelling of 12690221 in words is "twelve million, six hundred ninety thousand, two hundred twenty-one".