2222212121 has 4 divisors (see below), whose sum is σ = 2232744144. Its totient is φ = 2211680100.

The previous prime is 2222212117. The next prime is 2222212129. The reversal of 2222212121 is 1212122222.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2222212121 - 2² = 2222212117 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2222212121.

It is not an unprimeable number, because it can be changed into a prime (2222212129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5265695 + ... + 5266116.

It is an arithmetic number, because the mean of its divisors is an integer number (558186036).

Almost surely, 2^2222212121 is an apocalyptic number.

It is an amenable number.

2222212121 is a deficient number, since it is larger than the sum of its proper divisors (10532023).

2222212121 is a wasteful number, since it uses less digits than its factorization.

2222212121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10532022.

The product of its digits is 128, while the sum is 17.

The square root of 2222212121 is about 47140.3449393404. The cubic root of 2222212121 is about 1304.9539031392.

Adding to 2222212121 its reverse (1212122222), we get a palindrome (3434334343).

It can be divided in two parts, 22222 and 12121, that added together give a palindrome (34343).

The spelling of 2222212121 in words is "two billion, two hundred twenty-two million, two hundred twelve thousand, one hundred twenty-one".