680666844 has 96 divisors (see below), whose sum is σ = 1889879040. Its totient is φ = 187948800.

The previous prime is 680666821. The next prime is 680666879. The reversal of 680666844 is 448666086.

It is a junction number, because it is equal to n+sod(n) for n = 680666793 and 680666802.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 133054 + ... + 138074.

It is an arithmetic number, because the mean of its divisors is an integer number (19686240).

Almost surely, 2^680666844 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 680666844, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (944939520).

680666844 is an abundant number, since it is smaller than the sum of its proper divisors (1209212196).

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

680666844 is a wasteful number, since it uses less digits than its factorization.

680666844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5131 (or 5129 counting only the distinct ones).

The product of its (nonzero) digits is 1327104, while the sum is 48.

The square root of 680666844 is about 26089.5926376783. The cubic root of 680666844 is about 879.6532914496.

The spelling of 680666844 in words is "six hundred eighty million, six hundred sixty-six thousand, eight hundred forty-four".