1989687 has 8 divisors (see below), whose sum is σ = 3031936. Its totient is φ = 1136952.

The previous prime is 1989683. The next prime is 1989721. The reversal of 1989687 is 7869891.

It is a happy number.

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

It is not a de Polignac number, because 1989687 - 2² = 1989683 is a prime.

It is a Duffinian number.

1989687 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1989683) 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, 47353 + ... + 47394.

It is an arithmetic number, because the mean of its divisors is an integer number (378992).

2^1989687 is an apocalyptic number.

1989687 is a deficient number, since it is larger than the sum of its proper divisors (1042249).

1989687 is an equidigital number, since it uses as much as digits as its factorization.

1989687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94757.

The product of its digits is 217728, while the sum is 48.

The square root of 1989687 is about 1410.5626536953. The cubic root of 1989687 is about 125.7751722601.

The spelling of 1989687 in words is "one million, nine hundred eighty-nine thousand, six hundred eighty-seven".