680905871 has 4 divisors (see below), whose sum is σ = 681285744. Its totient is φ = 680526000.

The previous prime is 680905867. The next prime is 680905889. The reversal of 680905871 is 178509086.

It is a happy number.

680905871 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 680905871 - 2² = 680905867 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (680905861) 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, 187235 + ... + 190836.

It is an arithmetic number, because the mean of its divisors is an integer number (170321436).

Almost surely, 2^680905871 is an apocalyptic number.

680905871 is a deficient number, since it is larger than the sum of its proper divisors (379873).

680905871 is a wasteful number, since it uses less digits than its factorization.

680905871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 379872.

The product of its (nonzero) digits is 120960, while the sum is 44.

The square root of 680905871 is about 26094.1731235155. The cubic root of 680905871 is about 879.7562474854.

The spelling of 680905871 in words is "six hundred eighty million, nine hundred five thousand, eight hundred seventy-one".