681998740560 has 240 divisors, whose sum is σ = 2328456933504. Its totient is φ = 178851898368.

The previous prime is 681998740559. The next prime is 681998740567. The reversal of 681998740560 is 65047899186.

681998740560 is a `hidden beast` number, since 6 + 8 + 1 + 99 + 87 + 405 + 60 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a super-2 number, since 2×681998740560² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681998740567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 29559589 + ... + 29582651.

Almost surely, 2^681998740560 is an apocalyptic number.

681998740560 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 681998740560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1164228466752).

681998740560 is an abundant number, since it is smaller than the sum of its proper divisors (1646458192944).

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

681998740560 is a wasteful number, since it uses less digits than its factorization.

681998740560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23762 (or 23753 counting only the distinct ones).

The product of its (nonzero) digits is 26127360, while the sum is 63.

The spelling of 681998740560 in words is "six hundred eighty-one billion, nine hundred ninety-eight million, seven hundred forty thousand, five hundred sixty".