13231312421 has 4 divisors (see below), whose sum is σ = 13448219244. Its totient is φ = 13014405600.

The previous prime is 13231312387. The next prime is 13231312429. The reversal of 13231312421 is 12421313231.

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 2614276900 + 10617035521 = 51130^2 + 103039^2 .

It is a cyclic number.

It is not a de Polignac number, because 13231312421 - 2¹⁰ = 13231311397 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 (13231312429) 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, 108453320 + ... + 108453441.

It is an arithmetic number, because the mean of its divisors is an integer number (3362054811).

Almost surely, 2^13231312421 is an apocalyptic number.

It is an amenable number.

13231312421 is a deficient number, since it is larger than the sum of its proper divisors (216906823).

13231312421 is an equidigital number, since it uses as much as digits as its factorization.

13231312421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216906822.

The product of its digits is 864, while the sum is 23.

Adding to 13231312421 its reverse (12421313231), we get a palindrome (25652625652).

The spelling of 13231312421 in words is "thirteen billion, two hundred thirty-one million, three hundred twelve thousand, four hundred twenty-one".