681906272256 has 288 divisors, whose sum is σ = 2151635194800. Its totient is φ = 206338129920.

The previous prime is 681906272233. The next prime is 681906272261. The reversal of 681906272256 is 652272609186.

681906272256 is a `hidden beast` number, since 6 + 8 + 1 + 9 + 0 + 627 + 2 + 2 + 5 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 168079380 + ... + 168083436.

Almost surely, 2^681906272256 is an apocalyptic number.

681906272256 is a gapful number since it is divisible by the number (66) 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 681906272256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1075817597400).

681906272256 is an abundant number, since it is smaller than the sum of its proper divisors (1469728922544).

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

681906272256 is a wasteful number, since it uses less digits than its factorization.

681906272256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4925 (or 4902 counting only the distinct ones).

The product of its (nonzero) digits is 4354560, while the sum is 54.

The spelling of 681906272256 in words is "six hundred eighty-one billion, nine hundred six million, two hundred seventy-two thousand, two hundred fifty-six".