1687120 has 20 divisors (see below), whose sum is σ = 3922740. Its totient is φ = 674816.

The previous prime is 1687117. The next prime is 1687129. The reversal of 1687120 is 217861.

It can be written as a sum of positive squares in 2 ways, for example, as 1272384 + 414736 = 1128^2 + 644^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1687129) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 10465 + ... + 10624.

It is an arithmetic number, because the mean of its divisors is an integer number (196137).

2^1687120 is an apocalyptic number.

1687120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1687120 is an abundant number, since it is smaller than the sum of its proper divisors (2235620).

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

1687120 is a wasteful number, since it uses less digits than its factorization.

1687120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21102 (or 21096 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 1687120 is about 1298.8918353735. The cubic root of 1687120 is about 119.0461417467.

The spelling of 1687120 in words is "one million, six hundred eighty-seven thousand, one hundred twenty".