1212212212121 has 4 divisors (see below), whose sum is σ = 1283518812852. Its totient is φ = 1140905611392.

The previous prime is 1212212212063. The next prime is 1212212212187. The reversal of 1212212212121 is 1212122122121.

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 359923204096 + 852289008025 = 599936^2 + 923195^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212212212121 - 2¹⁰ = 1212212211097 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1212212212093 and 1212212212102.

It is not an unprimeable number, because it can be changed into a prime (1212212202121) 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, 35653300340 + ... + 35653300373.

It is an arithmetic number, because the mean of its divisors is an integer number (320879703213).

Almost surely, 2^{1212212212121} is an apocalyptic number.

It is an amenable number.

1212212212121 is a deficient number, since it is larger than the sum of its proper divisors (71306600731).

1212212212121 is an equidigital number, since it uses as much as digits as its factorization.

1212212212121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71306600730.

The product of its digits is 128, while the sum is 20.

Adding to 1212212212121 its reverse (1212122122121), we get a palindrome (2424334334242).

The spelling of 1212212212121 in words is "one trillion, two hundred twelve billion, two hundred twelve million, two hundred twelve thousand, one hundred twenty-one".