686447 has 4 divisors (see below), whose sum is σ = 689376. Its totient is φ = 683520.

The previous prime is 686437. The next prime is 686449. The reversal of 686447 is 744686.

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 686447 - 2¹⁶ = 620911 is a prime.

It is a Duffinian number.

It is a plaindrome in base 9.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 686447.

It is not an unprimeable number, because it can be changed into a prime (686449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1079 + ... + 1592.

It is an arithmetic number, because the mean of its divisors is an integer number (172344).

2⁶⁸⁶⁴⁴⁷ is an apocalyptic number.

686447 is a deficient number, since it is larger than the sum of its proper divisors (2929).

686447 is a wasteful number, since it uses less digits than its factorization.

686447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2928.

The product of its digits is 32256, while the sum is 35.

The square root of 686447 is about 828.5209713701. The cubic root of 686447 is about 88.2136252759.

The spelling of 686447 in words is "six hundred eighty-six thousand, four hundred forty-seven".