1689391 has 8 divisors (see below), whose sum is σ = 1861200. Its totient is φ = 1520640.

The previous prime is 1689379. The next prime is 1689397. The reversal of 1689391 is 1939861.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1689391 - 2⁷ = 1689263 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1689391.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1689397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 495 + ... + 1903.

It is an arithmetic number, because the mean of its divisors is an integer number (232650).

2^1689391 is an apocalyptic number.

1689391 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1689391 is a deficient number, since it is larger than the sum of its proper divisors (171809).

1689391 is a wasteful number, since it uses less digits than its factorization.

1689391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1529.

The product of its digits is 11664, while the sum is 37.

The square root of 1689391 is about 1299.7657481254. The cubic root of 1689391 is about 119.0995330433.

It can be divided in two parts, 1689 and 391, that added together give a triangular number (2080 = T₆₄).

The spelling of 1689391 in words is "one million, six hundred eighty-nine thousand, three hundred ninety-one".