13121213321 has 4 divisors (see below), whose sum is σ = 13121445444. Its totient is φ = 13120981200.

The previous prime is 13121213317. The next prime is 13121213323. The reversal of 13121213321 is 12331212131.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4103811721 + 9017401600 = 64061^2 + 94960^2 .

It is a cyclic number.

It is not a de Polignac number, because 13121213321 - 2² = 13121213317 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13121213293 and 13121213302.

It is not an unprimeable number, because it can be changed into a prime (13121213323) 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, 30011 + ... + 164751.

It is an arithmetic number, because the mean of its divisors is an integer number (3280361361).

Almost surely, 2^13121213321 is an apocalyptic number.

It is an amenable number.

13121213321 is a deficient number, since it is larger than the sum of its proper divisors (232123).

13121213321 is an equidigital number, since it uses as much as digits as its factorization.

13121213321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232122.

The product of its digits is 216, while the sum is 20.

Adding to 13121213321 its reverse (12331212131), we get a palindrome (25452425452).

The spelling of 13121213321 in words is "thirteen billion, one hundred twenty-one million, two hundred thirteen thousand, three hundred twenty-one".