663971684731264 has 768 divisors, whose sum is σ = 1741850437017600. Its totient is φ = 249578993664000.

The previous prime is 663971684731219. The next prime is 663971684731279. The reversal of 663971684731264 is 462137486179366.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 36142371999 + ... + 36142390369.

It is an arithmetic number, because the mean of its divisors is an integer number (2268034423200).

Almost surely, 2^{663971684731264} is an apocalyptic number.

663971684731264 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 663971684731264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (870925218508800).

663971684731264 is an abundant number, since it is smaller than the sum of its proper divisors (1077878752286336).

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

663971684731264 is a wasteful number, since it uses less digits than its factorization.

663971684731264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18703 (or 18684 counting only the distinct ones).

The product of its digits is 1316818944, while the sum is 73.

The spelling of 663971684731264 in words is "six hundred sixty-three trillion, nine hundred seventy-one billion, six hundred eighty-four million, seven hundred thirty-one thousand, two hundred sixty-four".