680891720 has 32 divisors (see below), whose sum is σ = 1535683320. Its totient is φ = 271703040.

The previous prime is 680891711. The next prime is 680891779. The reversal of 680891720 is 27198086.

It can be written as a sum of positive squares in 4 ways, for example, as 186540964 + 494350756 = 13658^2 + 22234^2 .

It is a super-2 number, since 2×680891720² = 927227068729116800, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3377 + ... + 37056.

Almost surely, 2^680891720 is an apocalyptic number.

It is an amenable number.

680891720 is an abundant number, since it is smaller than the sum of its proper divisors (854791600).

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

680891720 is a wasteful number, since it uses less digits than its factorization.

680891720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40865 (or 40861 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 41.

The square root of 680891720 is about 26093.9019696173. The cubic root of 680891720 is about 879.7501529000.

The spelling of 680891720 in words is "six hundred eighty million, eight hundred ninety-one thousand, seven hundred twenty".