686567640 has 128 divisors (see below), whose sum is σ = 2268414720. Its totient is φ = 164851200.

The previous prime is 686567611. The next prime is 686567647. The reversal of 686567640 is 46765686.

It is a self number, because there is not a number n which added to its sum of digits gives 686567640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686567647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 138810 + ... + 143670.

It is an arithmetic number, because the mean of its divisors is an integer number (17721990).

Almost surely, 2^686567640 is an apocalyptic number.

686567640 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 686567640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1134207360).

686567640 is an abundant number, since it is smaller than the sum of its proper divisors (1581847080).

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

686567640 is a wasteful number, since it uses less digits than its factorization.

686567640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4993 (or 4989 counting only the distinct ones).

The product of its (nonzero) digits is 1451520, while the sum is 48.

The square root of 686567640 is about 26202.4357646384. The cubic root of 686567640 is about 882.1879269037.

The spelling of 686567640 in words is "six hundred eighty-six million, five hundred sixty-seven thousand, six hundred forty".