12221220 has 48 divisors (see below), whose sum is σ = 37332288. Its totient is φ = 2962560.

The previous prime is 12221207. The next prime is 12221233. The reversal of 12221220 is 2212221.

It is an interprime number because it is at equal distance from previous prime (12221207) and next prime (12221233).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 12221196 and 12221205.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8599 + ... + 9918.

It is an arithmetic number, because the mean of its divisors is an integer number (777756).

Almost surely, 2^12221220 is an apocalyptic number.

12221220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12221220 is an abundant number, since it is smaller than the sum of its proper divisors (25111068).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12221220 is a wasteful number, since it uses less digits than its factorization.

12221220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18540 (or 18538 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 12221220 is about 3495.8861537527. The cubic root of 12221220 is about 230.3411446649.

Adding to 12221220 its reverse (2212221), we get a palindrome (14433441).

It can be divided in two parts, 1222 and 1220, that added together give a palindrome (2442).

The spelling of 12221220 in words is "twelve million, two hundred twenty-one thousand, two hundred twenty".