686907881 has 8 divisors (see below), whose sum is σ = 759620064. Its totient is φ = 615906720.

The previous prime is 686907869. The next prime is 686907911. The reversal of 686907881 is 188709686.

686907881 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-686907881 is a prime.

It is a super-2 number, since 2×686907881² = 943684873959820322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (686907841) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 426911 + ... + 428516.

It is an arithmetic number, because the mean of its divisors is an integer number (94952508).

Almost surely, 2^686907881 is an apocalyptic number.

It is an amenable number.

686907881 is a deficient number, since it is larger than the sum of its proper divisors (72712183).

686907881 is a wasteful number, since it uses less digits than its factorization.

686907881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 855511.

The product of its (nonzero) digits is 1161216, while the sum is 53.

The square root of 686907881 is about 26208.9275057184. The cubic root of 686907881 is about 882.3336308936. Note that the first 3 decimals are identical.

The spelling of 686907881 in words is "six hundred eighty-six million, nine hundred seven thousand, eight hundred eighty-one".