13112121221 has 4 divisors (see below), whose sum is σ = 13682213472. Its totient is φ = 12542028972.

The previous prime is 13112121151. The next prime is 13112121229. The reversal of 13112121221 is 12212121131.

It is a happy number.

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 not a de Polignac number, because 13112121221 - 2²² = 13107926917 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 13112121221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13112121229) 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, 285046091 + ... + 285046136.

It is an arithmetic number, because the mean of its divisors is an integer number (3420553368).

Almost surely, 2^13112121221 is an apocalyptic number.

It is an amenable number.

13112121221 is a deficient number, since it is larger than the sum of its proper divisors (570092251).

13112121221 is an equidigital number, since it uses as much as digits as its factorization.

13112121221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 570092250.

The product of its digits is 48, while the sum is 17.

Adding to 13112121221 its reverse (12212121131), we get a palindrome (25324242352).

The spelling of 13112121221 in words is "thirteen billion, one hundred twelve million, one hundred twenty-one thousand, two hundred twenty-one".