686340864 has 432 divisors, whose sum is σ = 2410611840. Its totient is φ = 192430080.

The previous prime is 686340839. The next prime is 686340871. The reversal of 686340864 is 468043686.

686340864 is a `hidden beast` number, since 6 + 8 + 634 + 0 + 8 + 6 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (432).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 11632867 + ... + 11632925.

It is an arithmetic number, because the mean of its divisors is an integer number (5580120).

Almost surely, 2^686340864 is an apocalyptic number.

686340864 is a gapful number since it is divisible by the number (64) 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 686340864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1205305920).

686340864 is an abundant number, since it is smaller than the sum of its proper divisors (1724270976).

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

686340864 is a wasteful number, since it uses less digits than its factorization.

686340864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118 (or 92 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 45.

The square root of 686340864 is about 26198.1080232905. The cubic root of 686340864 is about 882.0907861567.

The spelling of 686340864 in words is "six hundred eighty-six million, three hundred forty thousand, eight hundred sixty-four".