1681986686 has 8 divisors (see below), whose sum is σ = 2525664024. Its totient is φ = 840098680.

The previous prime is 1681986679. The next prime is 1681986707. The reversal of 1681986686 is 6866891861.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 444980 + ... + 448743.

It is an arithmetic number, because the mean of its divisors is an integer number (315708003).

Almost surely, 2^1681986686 is an apocalyptic number.

1681986686 is a deficient number, since it is larger than the sum of its proper divisors (843677338).

1681986686 is an equidigital number, since it uses as much as digits as its factorization.

1681986686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 894666.

The product of its digits is 5971968, while the sum is 59.

The square root of 1681986686 is about 41012.0309909178. The cubic root of 1681986686 is about 1189.2528054250.

The spelling of 1681986686 in words is "one billion, six hundred eighty-one million, nine hundred eighty-six thousand, six hundred eighty-six".