13644421205 has 4 divisors (see below), whose sum is σ = 16373305452. Its totient is φ = 10915536960.

The previous prime is 13644421199. The next prime is 13644421229. The reversal of 13644421205 is 50212444631.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50212444631 = 3607 ⋅13920833.

It can be written as a sum of positive squares in 2 ways, for example, as 4592230756 + 9052190449 = 67766^2 + 95143^2 .

It is not a de Polignac number, because 13644421205 - 2²⁶ = 13577312341 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1364442116 + ... + 1364442125.

It is an arithmetic number, because the mean of its divisors is an integer number (4093326363).

Almost surely, 2^13644421205 is an apocalyptic number.

It is an amenable number.

13644421205 is a deficient number, since it is larger than the sum of its proper divisors (2728884247).

13644421205 is an equidigital number, since it uses as much as digits as its factorization.

13644421205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2728884246.

The product of its (nonzero) digits is 23040, while the sum is 32.

Adding to 13644421205 its reverse (50212444631), we get a palindrome (63856865836).

The spelling of 13644421205 in words is "thirteen billion, six hundred forty-four million, four hundred twenty-one thousand, two hundred five".