18138377565 has 48 divisors (see below), whose sum is σ = 39197748096. Its totient is φ = 7538025600.

The previous prime is 18138377557. The next prime is 18138377591. The reversal of 18138377565 is 56577383181.

18138377565 is a `hidden beast` number, since 1 + 8 + 1 + 3 + 8 + 3 + 77 + 565 = 666.

It is not a de Polignac number, because 18138377565 - 2³ = 18138377557 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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, 2613906 + ... + 2620835.

It is an arithmetic number, because the mean of its divisors is an integer number (816619752).

Almost surely, 2^18138377565 is an apocalyptic number.

18138377565 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18138377565 is an abundant number, since it is smaller than the sum of its proper divisors (21059370531).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18138377565 is a wasteful number, since it uses less digits than its factorization.

18138377565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5234770 (or 5234767 counting only the distinct ones).

The product of its digits is 4233600, while the sum is 54.

The spelling of 18138377565 in words is "eighteen billion, one hundred thirty-eight million, three hundred seventy-seven thousand, five hundred sixty-five".