18643816550208 has 56 divisors (see below), whose sum is σ = 49364676236160. Its totient is φ = 6210039224320.

The previous prime is 18643816550207. The next prime is 18643816550231. The reversal of 18643816550208 is 80205561834681.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18643816550207) 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 7 ways as a sum of consecutive naturals, for example, 35412168 + ... + 35934791.

Almost surely, 2^{18643816550208} is an apocalyptic number.

It is an amenable number.

18643816550208 is an abundant number, since it is smaller than the sum of its proper divisors (30720859685952).

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

18643816550208 is a wasteful number, since it uses less digits than its factorization.

18643816550208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71348335 (or 71348325 counting only the distinct ones).

The product of its (nonzero) digits is 11059200, while the sum is 57.

The spelling of 18643816550208 in words is "eighteen trillion, six hundred forty-three billion, eight hundred sixteen million, five hundred fifty thousand, two hundred eight".