686688775718400 has 3600 divisors, whose sum is σ = 3330280089173664. Its totient is φ = 136357069455360.

The previous prime is 686688775718371. The next prime is 686688775718419. The reversal of 686688775718400 is 4817577886686.

686688775718400 is a `hidden beast` number, since 6 + 8 + 6 + 6 + 88 + 77 + 57 + 18 + 400 = 666.

It is a tau number, because it is divible by the number of its divisors (3600).

It is a Harshad number since it is a multiple of its sum of digits (81).

It is a self number, because there is not a number n which added to its sum of digits gives 686688775718400.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 359 ways as a sum of consecutive naturals, for example, 20851068334 + ... + 20851101266.

Almost surely, 2^{686688775718400} is an apocalyptic number.

686688775718400 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 686688775718400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1665140044586832).

686688775718400 is an abundant number, since it is smaller than the sum of its proper divisors (2643591313455264).

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

686688775718400 is a wasteful number, since it uses less digits than its factorization.

686688775718400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33023 (or 32980 counting only the distinct ones).

The product of its (nonzero) digits is 6069288960, while the sum is 81.

The spelling of 686688775718400 in words is "six hundred eighty-six trillion, six hundred eighty-eight billion, seven hundred seventy-five million, seven hundred eighteen thousand, four hundred".