1688004 has 18 divisors (see below), whose sum is σ = 4266990. Its totient is φ = 562656.

The previous prime is 1687999. The next prime is 1688041. The reversal of 1688004 is 4008861.

It can be written as a sum of positive squares in only one way, i.e., 1440000 + 248004 = 1200^2 + 498^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 23409 + ... + 23480.

It is an arithmetic number, because the mean of its divisors is an integer number (237055).

2^1688004 is an apocalyptic number.

It is an amenable number.

1688004 is an abundant number, since it is smaller than the sum of its proper divisors (2578986).

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

1688004 is a wasteful number, since it uses less digits than its factorization.

1688004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46899 (or 46894 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 1688004 is about 1299.2320808847. The cubic root of 1688004 is about 119.0669303123.

The spelling of 1688004 in words is "one million, six hundred eighty-eight thousand, four".