18517158408078 has 96 divisors (see below), whose sum is σ = 44125168988160. Its totient is φ = 5565472778880.

The previous prime is 18517158408019. The next prime is 18517158408079. The reversal of 18517158408078 is 87080485171581.

18517158408078 is a `hidden beast` number, since 1 + 8 + 5 + 1 + 7 + 158 + 408 + 0 + 78 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18517158408079) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 88635901 + ... + 88844567.

It is an arithmetic number, because the mean of its divisors is an integer number (459637176960).

Almost surely, 2^{18517158408078} is an apocalyptic number.

18517158408078 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18517158408078, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22062584494080).

18517158408078 is an abundant number, since it is smaller than the sum of its proper divisors (25608010580082).

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

18517158408078 is a wasteful number, since it uses less digits than its factorization.

18517158408078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212342 (or 212339 counting only the distinct ones).

The product of its (nonzero) digits is 20070400, while the sum is 63.

The spelling of 18517158408078 in words is "eighteen trillion, five hundred seventeen billion, one hundred fifty-eight million, four hundred eight thousand, seventy-eight".