681315618816 has 520 divisors, whose sum is σ = 2373909067200. Its totient is φ = 194629091328.

The previous prime is 681315618799. The next prime is 681315618833. The reversal of 681315618816 is 618816513186.

It is a happy number.

681315618816 is a `hidden beast` number, since 6 + 8 + 1 + 3 + 1 + 5 + 618 + 8 + 16 = 666.

It is an interprime number because it is at equal distance from previous prime (681315618799) and next prime (681315618833).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 113796175 + ... + 113802161.

Almost surely, 2^681315618816 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 681315618816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1186954533600).

681315618816 is an abundant number, since it is smaller than the sum of its proper divisors (1692593448384).

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

681315618816 is an frugal number, since it uses more digits than its factorization.

681315618816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6044 (or 5999 counting only the distinct ones).

The product of its digits is 1658880, while the sum is 54.

The spelling of 681315618816 in words is "six hundred eighty-one billion, three hundred fifteen million, six hundred eighteen thousand, eight hundred sixteen".