1687680 has 96 divisors (see below), whose sum is σ = 5847660. Its totient is φ = 448512.

The previous prime is 1687669. The next prime is 1687729. The reversal of 1687680 is 867861.

It can be written as a sum of positive squares in 2 ways, for example, as 1617984 + 69696 = 1272^2 + 264^2 .

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5614 + ... + 5906.

2^1687680 is an apocalyptic number.

1687680 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 1687680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2923830).

1687680 is an abundant number, since it is smaller than the sum of its proper divisors (4159980).

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

1687680 is a wasteful number, since it uses less digits than its factorization.

1687680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318 (or 303 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 1687680 is about 1299.1073858615. The cubic root of 1687680 is about 119.0593118166.

The spelling of 1687680 in words is "one million, six hundred eighty-seven thousand, six hundred eighty".