663984699840 has 1344 divisors, whose sum is σ = 3147762746880. Its totient is φ = 129839431680.

The previous prime is 663984699811. The next prime is 663984699871. The reversal of 663984699840 is 48996489366.

663984699840 is a `hidden beast` number, since 6 + 6 + 39 + 8 + 469 + 98 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (1344).

It is a super-2 number, since 2×663984699840² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is an unprimeable number.

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 191 ways as a sum of consecutive naturals, for example, 79164127 + ... + 79172513.

Almost surely, 2^663984699840 is an apocalyptic number.

663984699840 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 663984699840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1573881373440).

663984699840 is an abundant number, since it is smaller than the sum of its proper divisors (2483778047040).

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

663984699840 is a wasteful number, since it uses less digits than its factorization.

663984699840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8455 (or 8432 counting only the distinct ones).

The product of its (nonzero) digits is 483729408, while the sum is 72.

The spelling of 663984699840 in words is "six hundred sixty-three billion, nine hundred eighty-four million, six hundred ninety-nine thousand, eight hundred forty".