678209849856 has 640 divisors, whose sum is σ = 2554193664000. Its totient is φ = 176144855040.

The previous prime is 678209849843. The next prime is 678209849857. The reversal of 678209849856 is 658948902876.

678209849856 is a `hidden beast` number, since 6 + 7 + 82 + 0 + 9 + 8 + 498 + 56 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (678209849857) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 52151451 + ... + 52164453.

It is an arithmetic number, because the mean of its divisors is an integer number (3990927600).

Almost surely, 2^678209849856 is an apocalyptic number.

678209849856 is a gapful number since it is divisible by the number (66) 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 678209849856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1277096832000).

678209849856 is an abundant number, since it is smaller than the sum of its proper divisors (1875983814144).

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

678209849856 is a wasteful number, since it uses less digits than its factorization.

678209849856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13062 (or 13026 counting only the distinct ones).

The product of its (nonzero) digits is 418037760, while the sum is 72.

The spelling of 678209849856 in words is "six hundred seventy-eight billion, two hundred nine million, eight hundred forty-nine thousand, eight hundred fifty-six".