1212222222121 has 4 divisors (see below), whose sum is σ = 1215101610244. Its totient is φ = 1209342834000.

The previous prime is 1212222222103. The next prime is 1212222222151.

1212222222121 is nontrivially palindromic in base 10.

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 436704218896 + 775518003225 = 660836^2 + 880635^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212222222121 - 2¹⁹ = 1212221697833 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1212222222092 and 1212222222101.

It is not an unprimeable number, because it can be changed into a prime (1212222222151) 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, 1439693430 + ... + 1439694271.

It is an arithmetic number, because the mean of its divisors is an integer number (303775402561).

Almost surely, 2^{1212222222121} is an apocalyptic number.

It is an amenable number.

1212222222121 is a deficient number, since it is larger than the sum of its proper divisors (2879388123).

1212222222121 is an equidigital number, since it uses as much as digits as its factorization.

1212222222121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2879388122.

The product of its digits is 512, while the sum is 22.

Multiplying 1212222222121 by its sum of digits (22), we get a palindrome (26668888886662).

The spelling of 1212222222121 in words is "one trillion, two hundred twelve billion, two hundred twenty-two million, two hundred twenty-two thousand, one hundred twenty-one".