18538438425 has 48 divisors (see below), whose sum is σ = 33775629888. Its totient is φ = 8914348800.

The previous prime is 18538438381. The next prime is 18538438427. The reversal of 18538438425 is 52483483581.

It is not a de Polignac number, because 18538438425 - 2⁹ = 18538437913 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18538438427) 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 47 ways as a sum of consecutive naturals, for example, 179166 + ... + 263015.

It is an arithmetic number, because the mean of its divisors is an integer number (703658956).

Almost surely, 2^18538438425 is an apocalyptic number.

18538438425 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18538438425 is a deficient number, since it is larger than the sum of its proper divisors (15237191463).

18538438425 is a wasteful number, since it uses less digits than its factorization.

18538438425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 442250 (or 442245 counting only the distinct ones).

The product of its digits is 3686400, while the sum is 51.

The spelling of 18538438425 in words is "eighteen billion, five hundred thirty-eight million, four hundred thirty-eight thousand, four hundred twenty-five".