1688425 has 6 divisors (see below), whose sum is σ = 2093678. Its totient is φ = 1350720.

The previous prime is 1688413. The next prime is 1688443. The reversal of 1688425 is 5248861.

It can be written as a sum of positive squares in 3 ways, for example, as 1024 + 1687401 = 32^2 + 1299^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1688425 is a prime.

It is an Ulam number.

It is a Duffinian 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 5 ways as a sum of consecutive naturals, for example, 33744 + ... + 33793.

2^1688425 is an apocalyptic number.

It is an amenable number.

1688425 is a deficient number, since it is larger than the sum of its proper divisors (405253).

1688425 is an equidigital number, since it uses as much as digits as its factorization.

1688425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67547 (or 67542 counting only the distinct ones).

The product of its digits is 15360, while the sum is 34.

The square root of 1688425 is about 1299.3940895664. The cubic root of 1688425 is about 119.0768281978.

The spelling of 1688425 in words is "one million, six hundred eighty-eight thousand, four hundred twenty-five".