1686343680 has 312 divisors, whose sum is σ = 6685428672. Its totient is φ = 385155072.

The previous prime is 1686343669. The next prime is 1686343699. The reversal of 1686343680 is 863436861.

1686343680 is a `hidden beast` number, since 1 + 6 + 8 + 634 + 3 + 6 + 8 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1289587 + ... + 1290893.

It is an arithmetic number, because the mean of its divisors is an integer number (21427656).

Almost surely, 2^1686343680 is an apocalyptic number.

1686343680 is a gapful number since it is divisible by the number (10) 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 1686343680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3342714336).

1686343680 is an abundant number, since it is smaller than the sum of its proper divisors (4999084992).

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

1686343680 is a wasteful number, since it uses less digits than its factorization.

1686343680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1349 (or 1324 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 45.

The square root of 1686343680 is about 41065.1151222056. The cubic root of 1686343680 is about 1190.2787944578.

The spelling of 1686343680 in words is "one billion, six hundred eighty-six million, three hundred forty-three thousand, six hundred eighty".