1686634297920 has 1792 divisors, whose sum is σ = 7299984384000. Its totient is φ = 361091727360.

The previous prime is 1686634297903. The next prime is 1686634297939. The reversal of 1686634297920 is 297924366861.

1686634297920 is a `hidden beast` number, since 1 + 6 + 86 + 63 + 429 + 79 + 2 + 0 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 2815749781 + ... + 2815750379.

It is an arithmetic number, because the mean of its divisors is an integer number (4073652000).

Almost surely, 2^{1686634297920} is an apocalyptic number.

1686634297920 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 1686634297920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3649992192000).

1686634297920 is an abundant number, since it is smaller than the sum of its proper divisors (5613350086080).

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

1686634297920 is a wasteful number, since it uses less digits than its factorization.

1686634297920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 745 (or 729 counting only the distinct ones).

The product of its (nonzero) digits is 47029248, while the sum is 63.

The spelling of 1686634297920 in words is "one trillion, six hundred eighty-six billion, six hundred thirty-four million, two hundred ninety-seven thousand, nine hundred twenty".