18839081405 has 4 divisors (see below), whose sum is σ = 22606897692. Its totient is φ = 15071265120.

The previous prime is 18839081389. The next prime is 18839081407. The reversal of 18839081405 is 50418093881.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50418093881 = 149 ⋅338376469.

It can be written as a sum of positive squares in 2 ways, for example, as 3302456089 + 15536625316 = 57467^2 + 124646^2 .

It is not a de Polignac number, because 18839081405 - 2⁴ = 18839081389 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18839081405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18839081407) 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, 1883908136 + ... + 1883908145.

It is an arithmetic number, because the mean of its divisors is an integer number (5651724423).

Almost surely, 2^18839081405 is an apocalyptic number.

It is an amenable number.

18839081405 is a deficient number, since it is larger than the sum of its proper divisors (3767816287).

18839081405 is an equidigital number, since it uses as much as digits as its factorization.

18839081405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3767816286.

The product of its (nonzero) digits is 276480, while the sum is 47.

The spelling of 18839081405 in words is "eighteen billion, eight hundred thirty-nine million, eighty-one thousand, four hundred five".