12021222121 has 4 divisors (see below), whose sum is σ = 12728352852. Its totient is φ = 11314091392.

The previous prime is 12021222047. The next prime is 12021222163. The reversal of 12021222121 is 12122212021.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11201258896 + 819963225 = 105836^2 + 28635^2 .

It is a cyclic number.

It is not a de Polignac number, because 12021222121 - 2¹³ = 12021213929 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12021222095 and 12021222104.

It is not an unprimeable number, because it can be changed into a prime (12021222721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 353565340 + ... + 353565373.

It is an arithmetic number, because the mean of its divisors is an integer number (3182088213).

Almost surely, 2^12021222121 is an apocalyptic number.

It is an amenable number.

12021222121 is a deficient number, since it is larger than the sum of its proper divisors (707130731).

12021222121 is an equidigital number, since it uses as much as digits as its factorization.

12021222121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 707130730.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 12021222121 its reverse (12122212021), we get a palindrome (24143434142).

The spelling of 12021222121 in words is "twelve billion, twenty-one million, two hundred twenty-two thousand, one hundred twenty-one".