686813187 has 4 divisors (see below), whose sum is σ = 915750920. Its totient is φ = 457875456.

The previous prime is 686813173. The next prime is 686813207. The reversal of 686813187 is 781318686.

686813187 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 de Polignac number, because none of the positive numbers 2^k-686813187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (686813137) 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, 114468862 + ... + 114468867.

It is an arithmetic number, because the mean of its divisors is an integer number (228937730).

Almost surely, 2^686813187 is an apocalyptic number.

686813187 is a deficient number, since it is larger than the sum of its proper divisors (228937733).

686813187 is a wasteful number, since it uses less digits than its factorization.

686813187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228937732.

The product of its digits is 387072, while the sum is 48.

The square root of 686813187 is about 26207.1209216121. The cubic root of 686813187 is about 882.2930841949.

The spelling of 686813187 in words is "six hundred eighty-six million, eight hundred thirteen thousand, one hundred eighty-seven".