1686880 has 48 divisors (see below), whose sum is σ = 4297104. Its totient is φ = 622080.

The previous prime is 1686871. The next prime is 1686907. The reversal of 1686880 is 886861.

1686880 = 128² + 129² + ... + 192².

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 1675 + ... + 2485.

It is an arithmetic number, because the mean of its divisors is an integer number (89523).

2^1686880 is an apocalyptic number.

1686880 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 1686880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2148552).

1686880 is an abundant number, since it is smaller than the sum of its proper divisors (2610224).

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

1686880 is a wasteful number, since it uses less digits than its factorization.

1686880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 839 (or 831 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 37.

The square root of 1686880 is about 1298.7994456420. The cubic root of 1686880 is about 119.0404965390.

The spelling of 1686880 in words is "one million, six hundred eighty-six thousand, eight hundred eighty".