681553125847872 has 448 divisors, whose sum is σ = 2151382958592000. Its totient is φ = 210951680569344.

The previous prime is 681553125847861. The next prime is 681553125847907. The reversal of 681553125847872 is 278748521355186.

681553125847872 is a `hidden beast` number, since 6 + 8 + 1 + 5 + 5 + 31 + 2 + 58 + 478 + 72 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a self number, because there is not a number n which added to its sum of digits gives 681553125847872.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 354381723 + ... + 356299749.

It is an arithmetic number, because the mean of its divisors is an integer number (4802194104000).

Almost surely, 2^{681553125847872} 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 681553125847872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1075691479296000).

681553125847872 is an abundant number, since it is smaller than the sum of its proper divisors (1469829832744128).

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

681553125847872 is a wasteful number, since it uses less digits than its factorization.

681553125847872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1918283 (or 1918267 counting only the distinct ones).

The product of its digits is 903168000, while the sum is 72.

It can be divided in two parts, 6815531 and 25847872, that added together give a triangular number (32663403 = T₈₀₈₂).

The spelling of 681553125847872 in words is "six hundred eighty-one trillion, five hundred fifty-three billion, one hundred twenty-five million, eight hundred forty-seven thousand, eight hundred seventy-two".