1687920 has 80 divisors (see below), whose sum is σ = 5645472. Its totient is φ = 414720.

The previous prime is 1687909. The next prime is 1687937. The reversal of 1687920 is 297861.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2850 + ... + 3390.

2^1687920 is an apocalyptic number.

1687920 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 1687920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2822736).

1687920 is an abundant number, since it is smaller than the sum of its proper divisors (3957552).

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

1687920 is a wasteful number, since it uses less digits than its factorization.

1687920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 570 (or 564 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 1687920 is about 1299.1997536946. The cubic root of 1687920 is about 119.0649552404.

The spelling of 1687920 in words is "one million, six hundred eighty-seven thousand, nine hundred twenty".