1212121121021 has 16 divisors (see below), whose sum is σ = 1314792984960. Its totient is φ = 1112937745920.

The previous prime is 1212121120981. The next prime is 1212121121041. The reversal of 1212121121021 is 1201211212121.

It is a cyclic number.

It is not a de Polignac number, because 1212121121021 - 2¹⁴ = 1212121104637 is a prime.

It is a super-2 number, since 2×1212121121021² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212121121041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19866800 + ... + 19927718.

It is an arithmetic number, because the mean of its divisors is an integer number (82174561560).

Almost surely, 2^{1212121121021} is an apocalyptic number.

It is an amenable number.

1212121121021 is a deficient number, since it is larger than the sum of its proper divisors (102671863939).

1212121121021 is a wasteful number, since it uses less digits than its factorization.

1212121121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89524.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 1212121121021 its reverse (1201211212121), we get a palindrome (2413332333142).

The spelling of 1212121121021 in words is "one trillion, two hundred twelve billion, one hundred twenty-one million, one hundred twenty-one thousand, twenty-one".