1686685770 has 384 divisors, whose sum is σ = 5887365120. Its totient is φ = 324311040.

The previous prime is 1686685739. The next prime is 1686685831. The reversal of 1686685770 is 775866861.

1686685770 is a `hidden beast` number, since 1 + 6 + 8 + 6 + 68 + 577 + 0 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 12134361 + ... + 12134499.

It is an arithmetic number, because the mean of its divisors is an integer number (15331680).

Almost surely, 2^1686685770 is an apocalyptic number.

1686685770 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1686685770, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2943682560).

1686685770 is an abundant number, since it is smaller than the sum of its proper divisors (4200679350).

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

1686685770 is a wasteful number, since it uses less digits than its factorization.

1686685770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290 (or 287 counting only the distinct ones).

The product of its (nonzero) digits is 3386880, while the sum is 54.

The square root of 1686685770 is about 41069.2801251739. The cubic root of 1686685770 is about 1190.3592752731.

The spelling of 1686685770 in words is "one billion, six hundred eighty-six million, six hundred eighty-five thousand, seven hundred seventy".