2021121220 has 48 divisors (see below), whose sum is σ = 4288152960. Its totient is φ = 800151296.

The previous prime is 2021121209. The next prime is 2021121233. The reversal of 2021121220 is 221211202.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 2021121220.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 832929 + ... + 835351.

It is an arithmetic number, because the mean of its divisors is an integer number (89336520).

Almost surely, 2^2021121220 is an apocalyptic number.

2021121220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2021121220 is an abundant number, since it is smaller than the sum of its proper divisors (2267031740).

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

2021121220 is a wasteful number, since it uses less digits than its factorization.

2021121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2844 (or 2842 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 2021121220 is about 44956.8817868855. The cubic root of 2021121220 is about 1264.3407064051.

Adding to 2021121220 its reverse (221211202), we get a palindrome (2242332422).

The spelling of 2021121220 in words is "two billion, twenty-one million, one hundred twenty-one thousand, two hundred twenty".