686891867 has 4 divisors (see below), whose sum is σ = 689564856. Its totient is φ = 684218880.

The previous prime is 686891861. The next prime is 686891899. The reversal of 686891867 is 768198686.

686891867 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 686891867 - 2¹⁰ = 686890843 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (686891861) 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, 1336109 + ... + 1336622.

It is an arithmetic number, because the mean of its divisors is an integer number (172391214).

Almost surely, 2^686891867 is an apocalyptic number.

686891867 is a deficient number, since it is larger than the sum of its proper divisors (2672989).

686891867 is a wasteful number, since it uses less digits than its factorization.

686891867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2672988.

The product of its digits is 6967296, while the sum is 59.

The square root of 686891867 is about 26208.6219973504. The cubic root of 686891867 is about 882.3267741757.

The spelling of 686891867 in words is "six hundred eighty-six million, eight hundred ninety-one thousand, eight hundred sixty-seven".