12121101221 has 4 divisors (see below), whose sum is σ = 12127083072. Its totient is φ = 12115119372.

The previous prime is 12121101211. The next prime is 12121101229. The reversal of 12121101221 is 12210112121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12121101221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12121101196 and 12121101205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121101229) 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, 2987885 + ... + 2991938.

It is an arithmetic number, because the mean of its divisors is an integer number (3031770768).

Almost surely, 2^12121101221 is an apocalyptic number.

It is an amenable number.

12121101221 is a deficient number, since it is larger than the sum of its proper divisors (5981851).

12121101221 is an equidigital number, since it uses as much as digits as its factorization.

12121101221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5981850.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 12121101221 its reverse (12210112121), we get a palindrome (24331213342).

The spelling of 12121101221 in words is "twelve billion, one hundred twenty-one million, one hundred one thousand, two hundred twenty-one".