12121221220 has 48 divisors (see below), whose sum is σ = 25834717440. Its totient is φ = 4776355584.

The previous prime is 12121221199. The next prime is 12121221227. The reversal of 12121221220 is 2212212121.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 12121221194 and 12121221203.

It is not an unprimeable number, because it can be changed into a prime (12121221227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 713667 + ... + 730453.

It is an arithmetic number, because the mean of its divisors is an integer number (538223280).

Almost surely, 2^12121221220 is an apocalyptic number.

12121221220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12121221220 is an abundant number, since it is smaller than the sum of its proper divisors (13713496220).

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

12121221220 is a wasteful number, since it uses less digits than its factorization.

12121221220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17332 (or 17330 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 12121221220 its reverse (2212212121), we get a palindrome (14333433341).

Subtracting from 12121221220 its reverse (2212212121), we obtain a palindrome (9909009099).

The spelling of 12121221220 in words is "twelve billion, one hundred twenty-one million, two hundred twenty-one thousand, two hundred twenty".