686501 has 4 divisors (see below), whose sum is σ = 690252. Its totient is φ = 682752.

The previous prime is 686479. The next prime is 686503. The reversal of 686501 is 105686.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 122500 + 564001 = 350^2 + 751^2 .

It is a cyclic number.

It is not a de Polignac number, because 686501 - 2⁶ = 686437 is a prime.

It is an Ulam number.

It is a Duffinian number.

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 686501.

It is not an unprimeable number, because it can be changed into a prime (686503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1586 + ... + 1971.

It is an arithmetic number, because the mean of its divisors is an integer number (172563).

2⁶⁸⁶⁵⁰¹ is an apocalyptic number.

It is an amenable number.

686501 is a deficient number, since it is larger than the sum of its proper divisors (3751).

686501 is a wasteful number, since it uses less digits than its factorization.

686501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3750.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 686501 is about 828.5535589206. The cubic root of 686501 is about 88.2159383513.

The spelling of 686501 in words is "six hundred eighty-six thousand, five hundred one".