664788712500 has 432 divisors, whose sum is σ = 2353450619520. Its totient is φ = 156794400000.

The previous prime is 664788712451. The next prime is 664788712507. The reversal of 664788712500 is 5217887466.

664788712500 is a `hidden beast` number, since 6 + 6 + 47 + 8 + 87 + 12 + 500 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664788712507) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 45780241 + ... + 45794759.

It is an arithmetic number, because the mean of its divisors is an integer number (5447802360).

Almost surely, 2^664788712500 is an apocalyptic number.

664788712500 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 664788712500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1176725309760).

664788712500 is an abundant number, since it is smaller than the sum of its proper divisors (1688661907020).

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

664788712500 is a wasteful number, since it uses less digits than its factorization.

664788712500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14602 (or 14577 counting only the distinct ones).

The product of its (nonzero) digits is 4515840, while the sum is 54.

The spelling of 664788712500 in words is "six hundred sixty-four billion, seven hundred eighty-eight million, seven hundred twelve thousand, five hundred".