18438823489 has 4 divisors (see below), whose sum is σ = 18444498480. Its totient is φ = 18433148500.

The previous prime is 18438823369. The next prime is 18438823519. The reversal of 18438823489 is 98432883481.

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, and also an emirpimes, since its reverse is a distinct semiprime: 98432883481 = 38749 ⋅2540269.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18438823489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18438826489) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2832619 + ... + 2839120.

It is an arithmetic number, because the mean of its divisors is an integer number (4611124620).

Almost surely, 2^18438823489 is an apocalyptic number.

It is an amenable number.

18438823489 is a deficient number, since it is larger than the sum of its proper divisors (5674991).

18438823489 is an equidigital number, since it uses as much as digits as its factorization.

18438823489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5674990.

The product of its digits is 10616832, while the sum is 58.

The spelling of 18438823489 in words is "eighteen billion, four hundred thirty-eight million, eight hundred twenty-three thousand, four hundred eighty-nine".