221101220 has 24 divisors (see below), whose sum is σ = 480324600. Its totient is φ = 85390592.

The previous prime is 221101219. The next prime is 221101247. The reversal of 221101220 is 22101122.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 341056 + 220760164 = 584^2 + 14858^2 .

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, 190025 + ... + 191184.

It is an arithmetic number, because the mean of its divisors is an integer number (20013525).

Almost surely, 2^221101220 is an apocalyptic number.

221101220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221101220 is an abundant number, since it is smaller than the sum of its proper divisors (259223380).

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

221101220 is a wasteful number, since it uses less digits than its factorization.

221101220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 381247 (or 381245 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 221101220 is about 14869.4727546070. The cubic root of 221101220 is about 604.6866487423.

Adding to 221101220 its reverse (22101122), we get a palindrome (243202342).

The spelling of 221101220 in words is "two hundred twenty-one million, one hundred one thousand, two hundred twenty".