680831991 has 24 divisors (see below), whose sum is σ = 1124826144. Its totient is φ = 388730880.

The previous prime is 680831981. The next prime is 680832017. The reversal of 680831991 is 199138086.

It is not a de Polignac number, because 680831991 - 2⁷ = 680831863 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (680831911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 89655 + ... + 96951.

It is an arithmetic number, because the mean of its divisors is an integer number (46867756).

Almost surely, 2^680831991 is an apocalyptic number.

680831991 is a deficient number, since it is larger than the sum of its proper divisors (443994153).

680831991 is a wasteful number, since it uses less digits than its factorization.

680831991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8791 (or 8788 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The square root of 680831991 is about 26092.7574433980. The cubic root of 680831991 is about 879.7244277458.

The spelling of 680831991 in words is "six hundred eighty million, eight hundred thirty-one thousand, nine hundred ninety-one".