686843866 has 8 divisors (see below), whose sum is σ = 1033218900. Its totient is φ = 342437568.

The previous prime is 686843851. The next prime is 686843869. The reversal of 686843866 is 668348686.

It can be written as a sum of positive squares in 2 ways, for example, as 545923225 + 140920641 = 23365^2 + 11871^2 .

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

It is not an unprimeable number, because it can be changed into a prime (686843869) 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, 491311 + ... + 492706.

Almost surely, 2^686843866 is an apocalyptic number.

686843866 is a deficient number, since it is larger than the sum of its proper divisors (346375034).

686843866 is a wasteful number, since it uses less digits than its factorization.

686843866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 984368.

The product of its digits is 7962624, while the sum is 55.

The square root of 686843866 is about 26207.7062330911. The cubic root of 686843866 is about 882.3062209387.

The spelling of 686843866 in words is "six hundred eighty-six million, eight hundred forty-three thousand, eight hundred sixty-six".