686686520 has 64 divisors (see below), whose sum is σ = 1669943520. Its totient is φ = 252624384.

The previous prime is 686686519. The next prime is 686686523. The reversal of 686686520 is 25686686.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686686523) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 150107 + ... + 154613.

Almost surely, 2^686686520 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 686686520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (834971760).

686686520 is an abundant number, since it is smaller than the sum of its proper divisors (983257000).

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

686686520 is a wasteful number, since it uses less digits than its factorization.

686686520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4824 (or 4820 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 47.

The square root of 686686520 is about 26204.7041578416. The cubic root of 686686520 is about 882.2388412599.

The spelling of 686686520 in words is "six hundred eighty-six million, six hundred eighty-six thousand, five hundred twenty".