1688406 has 16 divisors (see below), whose sum is σ = 3575664. Its totient is φ = 529664.

The previous prime is 1688387. The next prime is 1688411. The reversal of 1688406 is 6048861.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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, 8175 + ... + 8378.

It is an arithmetic number, because the mean of its divisors is an integer number (223479).

2^1688406 is an apocalyptic number.

1688406 is an abundant number, since it is smaller than the sum of its proper divisors (1887258).

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

1688406 is a wasteful number, since it uses less digits than its factorization.

1688406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16575.

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 1688406 is about 1299.3867784459. The cubic root of 1688406 is about 119.0763815354.

The spelling of 1688406 in words is "one million, six hundred eighty-eight thousand, four hundred six".