681924568878 has 384 divisors, whose sum is σ = 1960824692736. Its totient is φ = 173112422400.

The previous prime is 681924568807. The next prime is 681924568879. The reversal of 681924568878 is 878865429186.

681924568878 is a `hidden beast` number, since 6 + 8 + 1 + 92 + 456 + 8 + 87 + 8 = 666.

It is a super-2 number, since 2×681924568878² (a number of 24 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681924568879) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 73502376 + ... + 73511652.

It is an arithmetic number, because the mean of its divisors is an integer number (5106314304).

Almost surely, 2^681924568878 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 681924568878, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (980412346368).

681924568878 is an abundant number, since it is smaller than the sum of its proper divisors (1278900123858).

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

681924568878 is a wasteful number, since it uses less digits than its factorization.

681924568878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9390 (or 9378 counting only the distinct ones).

The product of its digits is 371589120, while the sum is 72.

The spelling of 681924568878 in words is "six hundred eighty-one billion, nine hundred twenty-four million, five hundred sixty-eight thousand, eight hundred seventy-eight".