686426678784 has 1440 divisors, whose sum is σ = 2731758441984. Its totient is φ = 160871546880.

The previous prime is 686426678783. The next prime is 686426678789. The reversal of 686426678784 is 487876624686.

686426678784 is a `hidden beast` number, since 68 + 6 + 426 + 6 + 78 + 78 + 4 = 666.

686426678784 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×686426678784³ (a number of 36 digits) contains 333 as substring.

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

It is a nude number because it is divisible by every one of its digits.

Its product of digits (1040449536) is a multiple of the sum of its prime factors (336).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686426678783) 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, 2946037132 + ... + 2946037364.

Almost surely, 2^686426678784 is an apocalyptic number.

686426678784 is a gapful number since it is divisible by the number (64) 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 686426678784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1365879220992).

686426678784 is an abundant number, since it is smaller than the sum of its proper divisors (2045331763200).

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

686426678784 is a wasteful number, since it uses less digits than its factorization.

686426678784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336 (or 298 counting only the distinct ones).

The product of its digits is 1040449536, while the sum is 72.

The spelling of 686426678784 in words is "six hundred eighty-six billion, four hundred twenty-six million, six hundred seventy-eight thousand, seven hundred eighty-four".