1688397 has 12 divisors (see below), whose sum is σ = 2377440. Its totient is φ = 1065672.

The previous prime is 1688387. The next prime is 1688411. The reversal of 1688397 is 7938861.

It is not a de Polignac number, because 1688397 - 2¹⁰ = 1687373 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1688317) 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 11 ways as a sum of consecutive naturals, for example, 304 + ... + 1862.

It is an arithmetic number, because the mean of its divisors is an integer number (198120).

2^1688397 is an apocalyptic number.

It is an amenable number.

1688397 is a deficient number, since it is larger than the sum of its proper divisors (689043).

1688397 is a wasteful number, since it uses less digits than its factorization.

1688397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1600 (or 1581 counting only the distinct ones).

The product of its digits is 72576, while the sum is 42.

The square root of 1688397 is about 1299.3833152692. The cubic root of 1688397 is about 119.0761699572.

The spelling of 1688397 in words is "one million, six hundred eighty-eight thousand, three hundred ninety-seven".