1989663 has 16 divisors (see below), whose sum is σ = 3026016. Its totient is φ = 1152000.

The previous prime is 1989643. The next prime is 1989671. The reversal of 1989663 is 3669891.

It is not a de Polignac number, because 1989663 - 2⁹ = 1989151 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1989613) 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 15 ways as a sum of consecutive naturals, for example, 838 + ... + 2163.

It is an arithmetic number, because the mean of its divisors is an integer number (189126).

2^1989663 is an apocalyptic number.

1989663 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1989663 is a deficient number, since it is larger than the sum of its proper divisors (1036353).

1989663 is a wasteful number, since it uses less digits than its factorization.

1989663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3034.

The product of its digits is 69984, while the sum is 42.

The square root of 1989663 is about 1410.5541464261. The cubic root of 1989663 is about 125.7746665497.

The spelling of 1989663 in words is "one million, nine hundred eighty-nine thousand, six hundred sixty-three".