121242220 has 48 divisors (see below), whose sum is σ = 280270368. Its totient is φ = 43688960.

The previous prime is 121242193. The next prime is 121242221. The reversal of 121242220 is 22242121.

It is a junction number, because it is equal to n+sod(n) for n = 121242194 and 121242203.

It is not an unprimeable number, because it can be changed into a prime (121242221) 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, 22422 + ... + 27298.

It is an arithmetic number, because the mean of its divisors is an integer number (5838966).

Almost surely, 2^121242220 is an apocalyptic number.

121242220 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 121242220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (140135184).

121242220 is an abundant number, since it is smaller than the sum of its proper divisors (159028148).

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

121242220 is a wasteful number, since it uses less digits than its factorization.

121242220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5010 (or 5008 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 121242220 is about 11011.0044955036. The cubic root of 121242220 is about 494.9385632692.

Adding to 121242220 its reverse (22242121), we get a palindrome (143484341).

Subtracting from 121242220 its reverse (22242121), we obtain a palindrome (99000099).

The spelling of 121242220 in words is "one hundred twenty-one million, two hundred forty-two thousand, two hundred twenty".