686686440 has 256 divisors, whose sum is σ = 2418647040. Its totient is φ = 154112000.

The previous prime is 686686397. The next prime is 686686453. The reversal of 686686440 is 44686686.

It is a self number, because there is not a number n which added to its sum of digits gives 686686440.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1593025 + ... + 1593455.

It is an arithmetic number, because the mean of its divisors is an integer number (9447840).

Almost surely, 2^686686440 is an apocalyptic number.

686686440 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 686686440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1209323520).

686686440 is an abundant number, since it is smaller than the sum of its proper divisors (1731960600).

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

686686440 is a wasteful number, since it uses less digits than its factorization.

686686440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 544 (or 540 counting only the distinct ones).

The product of its (nonzero) digits is 1327104, while the sum is 48.

The square root of 686686440 is about 26204.7026313981. The cubic root of 686686440 is about 882.2388069992.

The spelling of 686686440 in words is "six hundred eighty-six million, six hundred eighty-six thousand, four hundred forty".