1686085640 has 32 divisors (see below), whose sum is σ = 3886225560. Its totient is φ = 657984000.

The previous prime is 1686085637. The next prime is 1686085649. The reversal of 1686085640 is 465806861.

It can be written as a sum of positive squares in 4 ways, for example, as 409738564 + 1276347076 = 20242^2 + 35726^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1686085591 and 1686085600.

It is not an unprimeable number, because it can be changed into a prime (1686085649) 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 7 ways as a sum of consecutive naturals, for example, 512411 + ... + 515690.

Almost surely, 2^1686085640 is an apocalyptic number.

1686085640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1686085640 is an abundant number, since it is smaller than the sum of its proper divisors (2200139920).

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

1686085640 is a wasteful number, since it uses less digits than its factorization.

1686085640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1028153 (or 1028149 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 44.

The square root of 1686085640 is about 41061.9731625259. The cubic root of 1686085640 is about 1190.2180802213.

The spelling of 1686085640 in words is "one billion, six hundred eighty-six million, eighty-five thousand, six hundred forty".