686940 has 36 divisors (see below), whose sum is σ = 1941576. Its totient is φ = 181472.

The previous prime is 686911. The next prime is 686947. The reversal of 686940 is 49686.

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686947) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6367 + ... + 6473.

2⁶⁸⁶⁹⁴⁰ is an apocalyptic number.

686940 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 686940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (970788).

686940 is an abundant number, since it is smaller than the sum of its proper divisors (1254636).

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

686940 is a wasteful number, since it uses less digits than its factorization.

686940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226 (or 117 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 686940 is about 828.8184360884. The cubic root of 686940 is about 88.2347382972.

The spelling of 686940 in words is "six hundred eighty-six thousand, nine hundred forty".