121121210220 has 96 divisors (see below), whose sum is σ = 341772189696. Its totient is φ = 32048736000.

The previous prime is 121121210201. The next prime is 121121210237. The reversal of 121121210220 is 22012121121.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 121121210220.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8518357 + ... + 8532563.

It is an arithmetic number, because the mean of its divisors is an integer number (3560126976).

Almost surely, 2^121121210220 is an apocalyptic number.

121121210220 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 121121210220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (170886094848).

121121210220 is an abundant number, since it is smaller than the sum of its proper divisors (220650979476).

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

121121210220 is a wasteful number, since it uses less digits than its factorization.

121121210220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15311 (or 15309 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 121121210220 its reverse (22012121121), we get a palindrome (143133331341).

The spelling of 121121210220 in words is "one hundred twenty-one billion, one hundred twenty-one million, two hundred ten thousand, two hundred twenty".