681961420800 has 1512 divisors, whose sum is σ = 2804987891160. Its totient is φ = 164229120000.

The previous prime is 681961420793. The next prime is 681961420817. The reversal of 681961420800 is 8024169186.

681961420800 is a `hidden beast` number, since 6 + 8 + 1 + 9 + 614 + 20 + 8 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 125 ways as a sum of consecutive naturals, for example, 4516300725 + ... + 4516300875.

Almost surely, 2^681961420800 is an apocalyptic number.

681961420800 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 681961420800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1402493945580).

681961420800 is an abundant number, since it is smaller than the sum of its proper divisors (2123026470360).

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

681961420800 is a wasteful number, since it uses less digits than its factorization.

681961420800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223 (or 172 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 45.

Adding to 681961420800 its reverse (8024169186), we get a palindrome (689985589986).

The spelling of 681961420800 in words is "six hundred eighty-one billion, nine hundred sixty-one million, four hundred twenty thousand, eight hundred".