13231031221 has 4 divisors (see below), whose sum is σ = 13806293472. Its totient is φ = 12655768972.

The previous prime is 13231031207. The next prime is 13231031249. The reversal of 13231031221 is 12213013231.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12213013231 = 17 ⋅718412543.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13231031221 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 (13231035221) 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, 287631091 + ... + 287631136.

It is an arithmetic number, because the mean of its divisors is an integer number (3451573368).

Almost surely, 2^13231031221 is an apocalyptic number.

It is an amenable number.

13231031221 is a deficient number, since it is larger than the sum of its proper divisors (575262251).

13231031221 is an equidigital number, since it uses as much as digits as its factorization.

13231031221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 575262250.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 13231031221 its reverse (12213013231), we get a palindrome (25444044452).

The spelling of 13231031221 in words is "thirteen billion, two hundred thirty-one million, thirty-one thousand, two hundred twenty-one".