2021021220 has 24 divisors (see below), whose sum is σ = 5658859584. Its totient is φ = 538938976.

The previous prime is 2021021207. The next prime is 2021021237. The reversal of 2021021220 is 221201202.

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 = 2021021196 and 2021021205.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16841784 + ... + 16841903.

It is an arithmetic number, because the mean of its divisors is an integer number (235785816).

Almost surely, 2^2021021220 is an apocalyptic number.

2021021220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2021021220 is an abundant number, since it is smaller than the sum of its proper divisors (3637838364).

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

2021021220 is a wasteful number, since it uses less digits than its factorization.

2021021220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33683699 (or 33683697 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 2021021220 is about 44955.7695963488. The cubic root of 2021021220 is about 1264.3198539273.

Adding to 2021021220 its reverse (221201202), we get a palindrome (2242222422).

The spelling of 2021021220 in words is "two billion, twenty-one million, twenty-one thousand, two hundred twenty".