686965 has 4 divisors (see below), whose sum is σ = 824364. Its totient is φ = 549568.

The previous prime is 686963. The next prime is 686969. The reversal of 686965 is 569686.

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 465124 + 221841 = 682^2 + 471^2 .

It is a cyclic number.

It is not a de Polignac number, because 686965 - 2¹ = 686963 is a prime.

It is a super-2 number, since 2×686965² = 943841822450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686963) 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, 68692 + ... + 68701.

It is an arithmetic number, because the mean of its divisors is an integer number (206091).

2⁶⁸⁶⁹⁶⁵ is an apocalyptic number.

It is an amenable number.

686965 is a deficient number, since it is larger than the sum of its proper divisors (137399).

686965 is a wasteful number, since it uses less digits than its factorization.

686965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137398.

The product of its digits is 77760, while the sum is 40.

The square root of 686965 is about 828.8335176620. The cubic root of 686965 is about 88.2358086680.

The spelling of 686965 in words is "six hundred eighty-six thousand, nine hundred sixty-five".