12121011220 has 96 divisors (see below), whose sum is σ = 27736642080. Its totient is φ = 4431298560.

The previous prime is 12121011173. The next prime is 12121011223. The reversal of 12121011220 is 2211012121.

It can be written as a sum of positive squares in 16 ways, for example, as 4710900496 + 7410110724 = 68636^2 + 86082^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 12121011220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121011223) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3190362 + ... + 3194158.

It is an arithmetic number, because the mean of its divisors is an integer number (288923355).

Almost surely, 2^12121011220 is an apocalyptic number.

12121011220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12121011220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13868321040).

12121011220 is an abundant number, since it is smaller than the sum of its proper divisors (15615630860).

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

12121011220 is a wasteful number, since it uses less digits than its factorization.

12121011220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4093 (or 4091 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 12121011220 its reverse (2211012121), we get a palindrome (14332023341).

Subtracting from 12121011220 its reverse (2211012121), we obtain a palindrome (9909999099).

The spelling of 12121011220 in words is "twelve billion, one hundred twenty-one million, eleven thousand, two hundred twenty".