18243773438 has 32 divisors (see below), whose sum is σ = 31600368000. Its totient is φ = 7812249120.

The previous prime is 18243773437. The next prime is 18243773447. The reversal of 18243773438 is 83437734281.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18243773437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47093 + ... + 196736.

It is an arithmetic number, because the mean of its divisors is an integer number (987511500).

Almost surely, 2^18243773438 is an apocalyptic number.

18243773438 is a deficient number, since it is larger than the sum of its proper divisors (13356594562).

18243773438 is a wasteful number, since it uses less digits than its factorization.

18243773438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244040.

The product of its digits is 2709504, while the sum is 50.

The spelling of 18243773438 in words is "eighteen billion, two hundred forty-three million, seven hundred seventy-three thousand, four hundred thirty-eight".