12221656 has 16 divisors (see below), whose sum is σ = 23239440. Its totient is φ = 6024480.

The previous prime is 12221611. The next prime is 12221669. The reversal of 12221656 is 65612221.

It is a self number, because there is not a number n which added to its sum of digits gives 12221656.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10191 + ... + 11326.

It is an arithmetic number, because the mean of its divisors is an integer number (1452465).

Almost surely, 2^12221656 is an apocalyptic number.

It is an amenable number.

12221656 is a deficient number, since it is larger than the sum of its proper divisors (11017784).

12221656 is a wasteful number, since it uses less digits than its factorization.

12221656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21594 (or 21590 counting only the distinct ones).

The product of its digits is 1440, while the sum is 25.

The square root of 12221656 is about 3495.9485122067. The cubic root of 12221656 is about 230.3438838225.

Adding to 12221656 its reverse (65612221), we get a palindrome (77833877).

The spelling of 12221656 in words is "twelve million, two hundred twenty-one thousand, six hundred fifty-six".