12122222121 has 12 divisors (see below), whose sum is σ = 17512946100. Its totient is φ = 8080064640.

The previous prime is 12122222117. The next prime is 12122222153.

It is a happy number.

12122222121 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 2 ways, for example, as 6230892096 + 5891330025 = 78936^2 + 76755^2 .

It is not a de Polignac number, because 12122222121 - 2² = 12122222117 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12122222094 and 12122222103.

It is not an unprimeable number, because it can be changed into a prime (12122222171) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 62500 + ... + 167781.

It is an arithmetic number, because the mean of its divisors is an integer number (1459412175).

Almost surely, 2^12122222121 is an apocalyptic number.

It is an amenable number.

12122222121 is a deficient number, since it is larger than the sum of its proper divisors (5390723979).

12122222121 is a wasteful number, since it uses less digits than its factorization.

12122222121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236136 (or 236133 counting only the distinct ones).

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

It can be divided in two parts, 121222 and 22121, that multiplied together give a palindrome (2681551862).

The spelling of 12122222121 in words is "twelve billion, one hundred twenty-two million, two hundred twenty-two thousand, one hundred twenty-one".