681663712752 has 720 divisors, whose sum is σ = 2315629540224. Its totient is φ = 192471552000.

The previous prime is 681663712657. The next prime is 681663712757. The reversal of 681663712752 is 257217366186.

681663712752 is a `hidden beast` number, since 68 + 166 + 371 + 2 + 7 + 52 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681663712757) 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, 1619153502 + ... + 1619153922.

Almost surely, 2^681663712752 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 681663712752, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1157814770112).

681663712752 is an abundant number, since it is smaller than the sum of its proper divisors (1633965827472).

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

681663712752 is a wasteful number, since it uses less digits than its factorization.

681663712752 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 620 (or 585 counting only the distinct ones).

The product of its digits is 5080320, while the sum is 54.

The spelling of 681663712752 in words is "six hundred eighty-one billion, six hundred sixty-three million, seven hundred twelve thousand, seven hundred fifty-two".