686421547776 has 576 divisors, whose sum is σ = 2160936422400. Its totient is φ = 217275125760.

The previous prime is 686421547699. The next prime is 686421547789. The reversal of 686421547776 is 677745124686.

686421547776 is a `hidden beast` number, since 6 + 8 + 64 + 21 + 547 + 7 + 7 + 6 = 666.

686421547776 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (576).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1087830981 + ... + 1087831611.

Almost surely, 2^686421547776 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 686421547776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1080468211200).

686421547776 is an abundant number, since it is smaller than the sum of its proper divisors (1474514874624).

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

686421547776 is an frugal number, since it uses more digits than its factorization.

686421547776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 764 (or 732 counting only the distinct ones).

The product of its digits is 94832640, while the sum is 63.

The spelling of 686421547776 in words is "six hundred eighty-six billion, four hundred twenty-one million, five hundred forty-seven thousand, seven hundred seventy-six".