681555896508 has 24 divisors (see below), whose sum is σ = 1683843980112. Its totient is φ = 213821457664.

The previous prime is 681555896503. The next prime is 681555896521. The reversal of 681555896508 is 805698555186.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681555896503) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1670479935 + ... + 1670480342.

It is an arithmetic number, because the mean of its divisors is an integer number (70160165838).

Almost surely, 2^681555896508 is an apocalyptic number.

681555896508 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

681555896508 is an abundant number, since it is smaller than the sum of its proper divisors (1002288083604).

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

681555896508 is a wasteful number, since it uses less digits than its factorization.

681555896508 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3340960301 (or 3340960299 counting only the distinct ones).

The product of its (nonzero) digits is 103680000, while the sum is 66.

The spelling of 681555896508 in words is "six hundred eighty-one billion, five hundred fifty-five million, eight hundred ninety-six thousand, five hundred eight".