12221222212121 has 4 divisors (see below), whose sum is σ = 13161316228452. Its totient is φ = 11281128195792.

The previous prime is 12221222212117. The next prime is 12221222212127. The reversal of 12221222212121 is 12121222212221.

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 5918807779600 + 6302414432521 = 2432860^2 + 2510461^2 .

It is not a de Polignac number, because 12221222212121 - 2² = 12221222212117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12221222212127) 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, 470047008146 + ... + 470047008171.

It is an arithmetic number, because the mean of its divisors is an integer number (3290329057113).

Almost surely, 2^{12221222212121} is an apocalyptic number.

It is an amenable number.

12221222212121 is a deficient number, since it is larger than the sum of its proper divisors (940094016331).

12221222212121 is an equidigital number, since it uses as much as digits as its factorization.

12221222212121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 940094016330.

The product of its digits is 512, while the sum is 23.

Adding to 12221222212121 its reverse (12121222212221), we get a palindrome (24342444424342).

The spelling of 12221222212121 in words is "twelve trillion, two hundred twenty-one billion, two hundred twenty-two million, two hundred twelve thousand, one hundred twenty-one".