12221620 has 12 divisors (see below), whose sum is σ = 25665444. Its totient is φ = 4888640.

The previous prime is 12221611. The next prime is 12221669. The reversal of 12221620 is 2612221.

It can be written as a sum of positive squares in 2 ways, for example, as 4963984 + 7257636 = 2228^2 + 2694^2 .

It is a junction number, because it is equal to n+sod(n) for n = 12221594 and 12221603.

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, 305521 + ... + 305560.

It is an arithmetic number, because the mean of its divisors is an integer number (2138787).

Almost surely, 2^12221620 is an apocalyptic number.

12221620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12221620 is an abundant number, since it is smaller than the sum of its proper divisors (13443824).

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

12221620 is a wasteful number, since it uses less digits than its factorization.

12221620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 611090 (or 611088 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 12221620 is about 3495.9433633856. The cubic root of 12221620 is about 230.3436576560.

Adding to 12221620 its reverse (2612221), we get a palindrome (14833841).

The spelling of 12221620 in words is "twelve million, two hundred twenty-one thousand, six hundred twenty".