663405872640 has 1920 divisors, whose sum is σ = 2783701831680. Its totient is φ = 133772083200.

The previous prime is 663405872611. The next prime is 663405872651. The reversal of 663405872640 is 46278504366.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (1920).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 9087751644 + ... + 9087751716.

It is an arithmetic number, because the mean of its divisors is an integer number (1449844704).

Almost surely, 2^663405872640 is an apocalyptic number.

663405872640 is a gapful number since it is divisible by the number (60) 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 663405872640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1391850915840).

663405872640 is an abundant number, since it is smaller than the sum of its proper divisors (2120295959040).

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

663405872640 is a wasteful number, since it uses less digits than its factorization.

663405872640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204 (or 181 counting only the distinct ones).

The product of its (nonzero) digits is 5806080, while the sum is 51.

The spelling of 663405872640 in words is "six hundred sixty-three billion, four hundred five million, eight hundred seventy-two thousand, six hundred forty".