18685351868538 has 32 divisors (see below), whose sum is σ = 38290143919104. Its totient is φ = 6076073917872.

The previous prime is 18685351868531. The next prime is 18685351868539. The reversal of 18685351868538 is 83586815358681.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 18685351868538.

It is not an unprimeable number, because it can be changed into a prime (18685351868531) 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, 107828920 + ... + 108002067.

It is an arithmetic number, because the mean of its divisors is an integer number (1196566997472).

Almost surely, 2^{18685351868538} is an apocalyptic number.

18685351868538 is an abundant number, since it is smaller than the sum of its proper divisors (19604792050566).

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

18685351868538 is a wasteful number, since it uses less digits than its factorization.

18685351868538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215831346.

The product of its digits is 1327104000, while the sum is 75.

The spelling of 18685351868538 in words is "eighteen trillion, six hundred eighty-five billion, three hundred fifty-one million, eight hundred sixty-eight thousand, five hundred thirty-eight".