222121212021 has 24 divisors (see below), whose sum is σ = 324580725144. Its totient is φ = 146360217600.

The previous prime is 222121212013. The next prime is 222121212041. The reversal of 222121212021 is 120212121222.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 172423427121 + 49697784900 = 415239^2 + 222930^2 .

It is not a de Polignac number, because 222121212021 - 2³ = 222121212013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 222121211985 and 222121212003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (222121212041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 312745 + ... + 736241.

It is an arithmetic number, because the mean of its divisors is an integer number (13524196881).

Almost surely, 2^222121212021 is an apocalyptic number.

It is an amenable number.

222121212021 is a deficient number, since it is larger than the sum of its proper divisors (102459513123).

222121212021 is a wasteful number, since it uses less digits than its factorization.

222121212021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 424181 (or 424178 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 222121212021 its reverse (120212121222), we get a palindrome (342333333243).

The spelling of 222121212021 in words is "two hundred twenty-two billion, one hundred twenty-one million, two hundred twelve thousand, twenty-one".