12121021221 has 8 divisors (see below), whose sum is σ = 16718650080. Its totient is φ = 7802036592.

The previous prime is 12121021201. The next prime is 12121021261. The reversal of 12121021221 is 12212012121.

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

It is not a de Polignac number, because 12121021221 - 2¹¹ = 12121019173 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12121021221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121021201) 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, 69660955 + ... + 69661128.

It is an arithmetic number, because the mean of its divisors is an integer number (2089831260).

Almost surely, 2^12121021221 is an apocalyptic number.

It is an amenable number.

12121021221 is a deficient number, since it is larger than the sum of its proper divisors (4597628859).

12121021221 is a wasteful number, since it uses less digits than its factorization.

12121021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139322115.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 12121021221 its reverse (12212012121), we get a palindrome (24333033342).

The spelling of 12121021221 in words is "twelve billion, one hundred twenty-one million, twenty-one thousand, two hundred twenty-one".