220021221 has 24 divisors (see below), whose sum is σ = 341883264. Its totient is φ = 125496000.

The previous prime is 220021183. The next prime is 220021253. The reversal of 220021221 is 122120022.

220021221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 220021221 - 2¹³ = 220013029 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 220021197 and 220021206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (220029221) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 109401 + ... + 111393.

It is an arithmetic number, because the mean of its divisors is an integer number (14245136).

Almost surely, 2^220021221 is an apocalyptic number.

220021221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

220021221 is a deficient number, since it is larger than the sum of its proper divisors (121862043).

220021221 is a wasteful number, since it uses less digits than its factorization.

220021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2761 (or 2754 counting only the distinct ones).

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

The square root of 220021221 is about 14833.1123167055. The cubic root of 220021221 is about 603.7004832316.

Adding to 220021221 its reverse (122120022), we get a palindrome (342141243).

The spelling of 220021221 in words is "two hundred twenty million, twenty-one thousand, two hundred twenty-one".