681619781700 has 576 divisors, whose sum is σ = 2578372473600. Its totient is φ = 152293478400.

The previous prime is 681619781681. The next prime is 681619781701. The reversal of 681619781700 is 7187916186.

681619781700 is a `hidden beast` number, since 6 + 8 + 1 + 619 + 7 + 8 + 17 + 0 + 0 = 666.

681619781700 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 Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (681619781701) 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, 398840446 + ... + 398842154.

It is an arithmetic number, because the mean of its divisors is an integer number (4476341100).

Almost surely, 2^681619781700 is an apocalyptic number.

681619781700 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 681619781700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1289186236800).

681619781700 is an abundant number, since it is smaller than the sum of its proper divisors (1896752691900).

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

681619781700 is a wasteful number, since it uses less digits than its factorization.

681619781700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2789 (or 2776 counting only the distinct ones).

The product of its (nonzero) digits is 1016064, while the sum is 54.

The spelling of 681619781700 in words is "six hundred eighty-one billion, six hundred nineteen million, seven hundred eighty-one thousand, seven hundred".