121221212102021 has 4 divisors (see below), whose sum is σ = 128351871637452. Its totient is φ = 114090552566592.

The previous prime is 121221212101961. The next prime is 121221212102033. The reversal of 121221212102021 is 120201212122121.

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 60172383211396 + 61048828890625 = 7757086^2 + 7813375^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121221212102021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121221212101984 and 121221212102002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121221212102071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3565329767690 + ... + 3565329767723.

It is an arithmetic number, because the mean of its divisors is an integer number (32087967909363).

Almost surely, 2^{121221212102021} is an apocalyptic number.

It is an amenable number.

121221212102021 is a deficient number, since it is larger than the sum of its proper divisors (7130659535431).

121221212102021 is an equidigital number, since it uses as much as digits as its factorization.

121221212102021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7130659535430.

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

Adding to 121221212102021 its reverse (120201212122121), we get a palindrome (241422424224142).

The spelling of 121221212102021 in words is "one hundred twenty-one trillion, two hundred twenty-one billion, two hundred twelve million, one hundred two thousand, twenty-one".