686961 has 24 divisors (see below), whose sum is σ = 1126944. Its totient is φ = 414720.

The previous prime is 686947. The next prime is 686963. The reversal of 686961 is 169686.

It is not a de Polignac number, because 686961 - 2⁶ = 686897 is a prime.

686961 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (686963) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2545 + ... + 2801.

It is an arithmetic number, because the mean of its divisors is an integer number (46956).

2⁶⁸⁶⁹⁶¹ is an apocalyptic number.

It is an amenable number.

686961 is a deficient number, since it is larger than the sum of its proper divisors (439983).

686961 is a wasteful number, since it uses less digits than its factorization.

686961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283 (or 271 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 686961 is about 828.8311046287. The cubic root of 686961 is about 88.2356374104.

The spelling of 686961 in words is "six hundred eighty-six thousand, nine hundred sixty-one".