6680815823681 has 4 divisors (see below), whose sum is σ = 6681794991552. Its totient is φ = 6679836655812.

The previous prime is 6680815823663. The next prime is 6680815823729. The reversal of 6680815823681 is 1863285180866.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6680815823681 - 2³⁸ = 6405937916737 is a prime.

It is a super-2 number, since 2×6680815823681² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6680815823651) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 489573701 + ... + 489587346.

It is an arithmetic number, because the mean of its divisors is an integer number (1670448747888).

Almost surely, 2^{6680815823681} is an apocalyptic number.

It is an amenable number.

6680815823681 is a deficient number, since it is larger than the sum of its proper divisors (979167871).

6680815823681 is an equidigital number, since it uses as much as digits as its factorization.

6680815823681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 979167870.

The product of its (nonzero) digits is 26542080, while the sum is 62.

The spelling of 6680815823681 in words is "six trillion, six hundred eighty billion, eight hundred fifteen million, eight hundred twenty-three thousand, six hundred eighty-one".