220021920 has 144 divisors (see below), whose sum is σ = 778770720. Its totient is φ = 58662144.

The previous prime is 220021897. The next prime is 220021981. The reversal of 220021920 is 29120022.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 220021893 and 220021902.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 36051 + ... + 41709.

It is an arithmetic number, because the mean of its divisors is an integer number (5408130).

Almost surely, 2^220021920 is an apocalyptic number.

220021920 is a gapful number since it is divisible by the number (20) 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 220021920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (389385360).

220021920 is an abundant number, since it is smaller than the sum of its proper divisors (558748800).

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

220021920 is an equidigital number, since it uses as much as digits as its factorization.

220021920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5689 (or 5669 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 220021920 is about 14833.1358788356. The cubic root of 220021920 is about 603.7011225429.

Adding to 220021920 its reverse (29120022), we get a palindrome (249141942).

The spelling of 220021920 in words is "two hundred twenty million, twenty-one thousand, nine hundred twenty".