13131212221 has 16 divisors (see below), whose sum is σ = 13978828800. Its totient is φ = 12316172400.

The previous prime is 13131212219. The next prime is 13131212239. The reversal of 13131212221 is 12221213131.

It is a cyclic number.

It is not a de Polignac number, because 13131212221 - 2¹ = 13131212219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13131212251) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 79300 + ... + 180418.

It is an arithmetic number, because the mean of its divisors is an integer number (873676800).

Almost surely, 2^13131212221 is an apocalyptic number.

It is an amenable number.

13131212221 is a deficient number, since it is larger than the sum of its proper divisors (847616579).

13131212221 is a wasteful number, since it uses less digits than its factorization.

13131212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101280.

The product of its digits is 144, while the sum is 19.

Adding to 13131212221 its reverse (12221213131), we get a palindrome (25352425352).

The spelling of 13131212221 in words is "thirteen billion, one hundred thirty-one million, two hundred twelve thousand, two hundred twenty-one".