663818635216 has 80 divisors (see below), whose sum is σ = 1469773392768. Its totient is φ = 287493324800.

The previous prime is 663818635199. The next prime is 663818635217. The reversal of 663818635216 is 612536818366.

It is a Smith number, since the sum of its digits (55) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663818635217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 721296 + ... + 1359376.

Almost surely, 2^663818635216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 663818635216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (734886696384).

663818635216 is an abundant number, since it is smaller than the sum of its proper divisors (805954757552).

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

663818635216 is a wasteful number, since it uses less digits than its factorization.

663818635216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 638380 (or 638374 counting only the distinct ones).

The product of its digits is 7464960, while the sum is 55.

The spelling of 663818635216 in words is "six hundred sixty-three billion, eight hundred eighteen million, six hundred thirty-five thousand, two hundred sixteen".