12121211110021 has 8 divisors (see below), whose sum is σ = 13053753137880. Its totient is φ = 11188689249792.

The previous prime is 12121211110009. The next prime is 12121211110037. The reversal of 12121211110021 is 12001111212121.

It can be written as a sum of positive squares in 4 ways, for example, as 369924269796 + 11751286840225 = 608214^2 + 3428015^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12121211110021 - 2³⁷ = 11983772156549 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12121211109977 and 12121211110004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121211110121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3781960 + ... + 6208513.

It is an arithmetic number, because the mean of its divisors is an integer number (1631719142235).

Almost surely, 2^{12121211110021} is an apocalyptic number.

It is an amenable number.

12121211110021 is a deficient number, since it is larger than the sum of its proper divisors (932542027859).

12121211110021 is an equidigital number, since it uses as much as digits as its factorization.

12121211110021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10083815.

The product of its (nonzero) digits is 16, while the sum is 16.

Adding to 12121211110021 its reverse (12001111212121), we get a palindrome (24122322322142).

The spelling of 12121211110021 in words is "twelve trillion, one hundred twenty-one billion, two hundred eleven million, one hundred ten thousand, twenty-one".