221222020 has 48 divisors (see below), whose sum is σ = 494868528. Its totient is φ = 82780160.

The previous prime is 221222011. The next prime is 221222039. The reversal of 221222020 is 20222122.

It can be written as a sum of positive squares in 8 ways, for example, as 18045504 + 203176516 = 4248^2 + 14254^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 56940 + ... + 60700.

It is an arithmetic number, because the mean of its divisors is an integer number (10309761).

Almost surely, 2^221222020 is an apocalyptic number.

221222020 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 221222020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (247434264).

221222020 is an abundant number, since it is smaller than the sum of its proper divisors (273646508).

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

221222020 is a wasteful number, since it uses less digits than its factorization.

221222020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3960 (or 3958 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 13.

The square root of 221222020 is about 14873.5342134948. The cubic root of 221222020 is about 604.7967534388.

Adding to 221222020 its reverse (20222122), we get a palindrome (241444142).

It can be divided in two parts, 22122 and 2020, that added together give a palindrome (24142).

The spelling of 221222020 in words is "two hundred twenty-one million, two hundred twenty-two thousand, twenty".