18912138905 has 8 divisors (see below), whose sum is σ = 24757709184. Its totient is φ = 13754282800.

The previous prime is 18912138829. The next prime is 18912138919. The reversal of 18912138905 is 50983121981.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-18912138905 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 18912138905.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 171928481 + ... + 171928590.

It is an arithmetic number, because the mean of its divisors is an integer number (3094713648).

Almost surely, 2^18912138905 is an apocalyptic number.

It is an amenable number.

18912138905 is a deficient number, since it is larger than the sum of its proper divisors (5845570279).

18912138905 is a wasteful number, since it uses less digits than its factorization.

18912138905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 343857087.

The product of its (nonzero) digits is 155520, while the sum is 47.

The spelling of 18912138905 in words is "eighteen billion, nine hundred twelve million, one hundred thirty-eight thousand, nine hundred five".