1989705 has 8 divisors (see below), whose sum is σ = 3183552. Its totient is φ = 1061168.

The previous prime is 1989683. The next prime is 1989721. The reversal of 1989705 is 5079891.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 1989705 - 2⁹ = 1989193 is a prime.

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, 66309 + ... + 66338.

It is an arithmetic number, because the mean of its divisors is an integer number (397944).

2^1989705 is an apocalyptic number.

1989705 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1989705 is a deficient number, since it is larger than the sum of its proper divisors (1193847).

1989705 is a wasteful number, since it uses less digits than its factorization.

1989705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132655.

The product of its (nonzero) digits is 22680, while the sum is 39.

The square root of 1989705 is about 1410.5690341135. The cubic root of 1989705 is about 125.7755515403.

The spelling of 1989705 in words is "one million, nine hundred eighty-nine thousand, seven hundred five".