128989549 has 4 divisors (see below), whose sum is σ = 138911836. Its totient is φ = 119067264.

The previous prime is 128989501. The next prime is 128989559. The reversal of 128989549 is 945989821.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18361225 + 110628324 = 4285^2 + 10518^2 .

It is a cyclic number.

It is not a de Polignac number, because 128989549 - 2¹⁹ = 128465261 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 128989549.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128989559) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4961124 + ... + 4961149.

It is an arithmetic number, because the mean of its divisors is an integer number (34727959).

Almost surely, 2^128989549 is an apocalyptic number.

It is an amenable number.

128989549 is a deficient number, since it is larger than the sum of its proper divisors (9922287).

128989549 is an equidigital number, since it uses as much as digits as its factorization.

128989549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9922286.

The product of its digits is 1866240, while the sum is 55.

The square root of 128989549 is about 11357.3566026607. The cubic root of 128989549 is about 505.2637892504.

The spelling of 128989549 in words is "one hundred twenty-eight million, nine hundred eighty-nine thousand, five hundred forty-nine".