13404043131221 has 4 divisors (see below), whose sum is σ = 13404199080000. Its totient is φ = 13403887182444.

The previous prime is 13404043131161. The next prime is 13404043131233. The reversal of 13404043131221 is 12213134040431.

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 a de Polignac number, because none of the positive numbers 2^k-13404043131221 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 (13404043131251) 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, 77845391 + ... + 78017388.

It is an arithmetic number, because the mean of its divisors is an integer number (3351049770000).

Almost surely, 2^{13404043131221} is an apocalyptic number.

It is an amenable number.

13404043131221 is a deficient number, since it is larger than the sum of its proper divisors (155948779).

13404043131221 is an equidigital number, since it uses as much as digits as its factorization.

13404043131221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155948778.

The product of its (nonzero) digits is 6912, while the sum is 29.

Adding to 13404043131221 its reverse (12213134040431), we get a palindrome (25617177171652).

The spelling of 13404043131221 in words is "thirteen trillion, four hundred four billion, forty-three million, one hundred thirty-one thousand, two hundred twenty-one".