18443688436 has 12 divisors (see below), whose sum is σ = 33975215680. Its totient is φ = 8736483960.

The previous prime is 18443688409. The next prime is 18443688437. The reversal of 18443688436 is 63488634481.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18443688437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121339980 + ... + 121340131.

Almost surely, 2^18443688436 is an apocalyptic number.

It is an amenable number.

18443688436 is a deficient number, since it is larger than the sum of its proper divisors (15531527244).

18443688436 is a wasteful number, since it uses less digits than its factorization.

18443688436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242680134 (or 242680132 counting only the distinct ones).

The product of its digits is 10616832, while the sum is 55.

The spelling of 18443688436 in words is "eighteen billion, four hundred forty-three million, six hundred eighty-eight thousand, four hundred thirty-six".