13805949817 has 4 divisors (see below), whose sum is σ = 15061036176. Its totient is φ = 12550863460.

The previous prime is 13805949809. The next prime is 13805949821. The reversal of 13805949817 is 71894950831.

It is a happy number.

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 not a de Polignac number, because 13805949817 - 2³ = 13805949809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13805947817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 627543163 + ... + 627543184.

It is an arithmetic number, because the mean of its divisors is an integer number (3765259044).

Almost surely, 2^13805949817 is an apocalyptic number.

It is an amenable number.

13805949817 is a deficient number, since it is larger than the sum of its proper divisors (1255086359).

13805949817 is a wasteful number, since it uses less digits than its factorization.

13805949817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1255086358.

The product of its (nonzero) digits is 2177280, while the sum is 55.

The spelling of 13805949817 in words is "thirteen billion, eight hundred five million, nine hundred forty-nine thousand, eight hundred seventeen".