1989128 has 8 divisors (see below), whose sum is σ = 3729630. Its totient is φ = 994560.

The previous prime is 1989107. The next prime is 1989131. The reversal of 1989128 is 8219891.

It can be written as a sum of positive squares in only one way, i.e., 1737124 + 252004 = 1318^2 + 502^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 1989091 and 1989100.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124313 + ... + 124328.

2^1989128 is an apocalyptic number.

It is an amenable number.

1989128 is a deficient number, since it is larger than the sum of its proper divisors (1740502).

1989128 is a wasteful number, since it uses less digits than its factorization.

1989128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 248647 (or 248643 counting only the distinct ones).

The product of its digits is 10368, while the sum is 38.

The square root of 1989128 is about 1410.3644918956. The cubic root of 1989128 is about 125.7633923660.

The spelling of 1989128 in words is "one million, nine hundred eighty-nine thousand, one hundred twenty-eight".