681145936128 has 972 divisors, whose sum is σ = 2504458298160. Its totient is φ = 184072476672.

The previous prime is 681145936127. The next prime is 681145936189. The reversal of 681145936128 is 821639541186.

It is a happy number.

681145936128 is a `hidden beast` number, since 6 + 8 + 1 + 14 + 5 + 9 + 3 + 612 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (972).

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 (681145936127) by changing a digit.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 1100397003 + ... + 1100397621.

Almost surely, 2^681145936128 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 681145936128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1252229149080).

681145936128 is an abundant number, since it is smaller than the sum of its proper divisors (1823312362032).

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

681145936128 is an equidigital number, since it uses as much as digits as its factorization.

681145936128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 702 (or 650 counting only the distinct ones).

The product of its digits is 2488320, while the sum is 54.

The spelling of 681145936128 in words is "six hundred eighty-one billion, one hundred forty-five million, nine hundred thirty-six thousand, one hundred twenty-eight".