121221110220 has 48 divisors (see below), whose sum is σ = 387907554048. Its totient is φ = 27707682240.

The previous prime is 121221110147. The next prime is 121221110221. The reversal of 121221110220 is 22011122121.

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 121221110220.

It is not an unprimeable number, because it can be changed into a prime (121221110221) 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, 144310426 + ... + 144311265.

It is an arithmetic number, because the mean of its divisors is an integer number (8081407376).

Almost surely, 2^121221110220 is an apocalyptic number.

121221110220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121221110220 is an abundant number, since it is smaller than the sum of its proper divisors (266686443828).

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

121221110220 is a wasteful number, since it uses less digits than its factorization.

121221110220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288621710 (or 288621708 counting only the distinct ones).

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

Adding to 121221110220 its reverse (22011122121), we get a palindrome (143232232341).

The spelling of 121221110220 in words is "one hundred twenty-one billion, two hundred twenty-one million, one hundred ten thousand, two hundred twenty".