1989664 has 24 divisors (see below), whose sum is σ = 3963708. Its totient is φ = 983040.

The previous prime is 1989643. The next prime is 1989671. The reversal of 1989664 is 4669891.

It can be written as a sum of positive squares in 2 ways, for example, as 1904400 + 85264 = 1380^2 + 292^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1989664.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2784 + ... + 3424.

2^1989664 is an apocalyptic number.

It is an amenable number.

1989664 is a deficient number, since it is larger than the sum of its proper divisors (1974044).

1989664 is an equidigital number, since it uses as much as digits as its factorization.

1989664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 748 (or 740 counting only the distinct ones).

The product of its digits is 93312, while the sum is 43.

The square root of 1989664 is about 1410.5545008967. The cubic root of 1989664 is about 125.7746876211.

The spelling of 1989664 in words is "one million, nine hundred eighty-nine thousand, six hundred sixty-four".