121121220 has 192 divisors, whose sum is σ = 394813440. Its totient is φ = 27456000.

The previous prime is 121121213. The next prime is 121121227. The reversal of 121121220 is 22121121.

It is an interprime number because it is at equal distance from previous prime (121121213) and next prime (121121227).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 121121196 and 121121205.

It is not an unprimeable number, because it can be changed into a prime (121121227) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1199170 + ... + 1199270.

It is an arithmetic number, because the mean of its divisors is an integer number (2056320).

Almost surely, 2^121121220 is an apocalyptic number.

121121220 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 121121220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (197406720).

121121220 is an abundant number, since it is smaller than the sum of its proper divisors (273692220).

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

121121220 is a wasteful number, since it uses less digits than its factorization.

121121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226 (or 224 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 121121220 is about 11005.5086206863. The cubic root of 121121220 is about 494.7738585433.

Adding to 121121220 its reverse (22121121), we get a palindrome (143242341).

Subtracting from 121121220 its reverse (22121121), we obtain a palindrome (99000099).

The spelling of 121121220 in words is "one hundred twenty-one million, one hundred twenty-one thousand, two hundred twenty".