12121644 has 48 divisors (see below), whose sum is σ = 30336768. Its totient is φ = 3757248.

The previous prime is 12121631. The next prime is 12121661. The reversal of 12121644 is 44612121.

It is a happy number.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 12121644.

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, 9619 + ... + 10805.

It is an arithmetic number, because the mean of its divisors is an integer number (632016).

Almost surely, 2^12121644 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12121644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15168384).

12121644 is an abundant number, since it is smaller than the sum of its proper divisors (18215124).

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

12121644 is a wasteful number, since it uses less digits than its factorization.

12121644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1254 (or 1252 counting only the distinct ones).

The product of its digits is 384, while the sum is 21.

The square root of 12121644 is about 3481.6151424303. The cubic root of 12121644 is about 229.7138470309.

Adding to 12121644 its reverse (44612121), we get a palindrome (56733765).

The spelling of 12121644 in words is "twelve million, one hundred twenty-one thousand, six hundred forty-four".