686740 has 12 divisors (see below), whose sum is σ = 1442196. Its totient is φ = 274688.

The previous prime is 686737. The next prime is 686761. The reversal of 686740 is 47686.

686740 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 274576 + 412164 = 524^2 + 642^2 .

It is a super-2 number, since 2×686740² = 943223655200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17149 + ... + 17188.

It is an arithmetic number, because the mean of its divisors is an integer number (120183).

2⁶⁸⁶⁷⁴⁰ is an apocalyptic number.

It is an amenable number.

686740 is an abundant number, since it is smaller than the sum of its proper divisors (755456).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

686740 is a wasteful number, since it uses less digits than its factorization.

686740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34346 (or 34344 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 686740 is about 828.6977736183. The cubic root of 686740 is about 88.2261743951.

The spelling of 686740 in words is "six hundred eighty-six thousand, seven hundred forty".