222121220 has 24 divisors (see below), whose sum is σ = 471077208. Its totient is φ = 87968000.

The previous prime is 222121217. The next prime is 222121223. The reversal of 222121220 is 22121222.

It is an interprime number because it is at equal distance from previous prime (222121217) and next prime (222121223).

It can be written as a sum of positive squares in 4 ways, for example, as 146361604 + 75759616 = 12098^2 + 8704^2 .

It is a junction number, because it is equal to n+sod(n) for n = 222121195 and 222121204.

It is not an unprimeable number, because it can be changed into a prime (222121223) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 52961 + ... + 57000.

It is an arithmetic number, because the mean of its divisors is an integer number (19628217).

Almost surely, 2^222121220 is an apocalyptic number.

222121220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

222121220 is an abundant number, since it is smaller than the sum of its proper divisors (248955988).

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

222121220 is a wasteful number, since it uses less digits than its factorization.

222121220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110071 (or 110069 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 222121220 is about 14903.7317474517. The cubic root of 222121220 is about 605.6150837620.

Adding to 222121220 its reverse (22121222), we get a palindrome (244242442).

It can be divided in two parts, 22212 and 1220, that added together give a palindrome (23432).

The spelling of 222121220 in words is "two hundred twenty-two million, one hundred twenty-one thousand, two hundred twenty".