1687406 has 16 divisors (see below), whose sum is σ = 2961024. Its totient is φ = 706104.

The previous prime is 1687393. The next prime is 1687421. The reversal of 1687406 is 6047861.

1687406 = 648² + 649² + ... + 651².

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 800 + ... + 2003.

It is an arithmetic number, because the mean of its divisors is an integer number (185064).

2^1687406 is an apocalyptic number.

1687406 is a deficient number, since it is larger than the sum of its proper divisors (1273618).

1687406 is a wasteful number, since it uses less digits than its factorization.

1687406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2855.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 1687406 is about 1299.0019245559. The cubic root of 1687406 is about 119.0528682536.

The spelling of 1687406 in words is "one million, six hundred eighty-seven thousand, four hundred six".