128649789 has 12 divisors (see below), whose sum is σ = 192710336. Its totient is φ = 85766364.

The previous prime is 128649749. The next prime is 128649803. The reversal of 128649789 is 987946821.

It is not a de Polignac number, because 128649789 - 2⁸ = 128649533 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128649749) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 264469 + ... + 264954.

Almost surely, 2^128649789 is an apocalyptic number.

It is an amenable number.

128649789 is a deficient number, since it is larger than the sum of its proper divisors (64060547).

128649789 is an frugal number, since it uses more digits than its factorization.

128649789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 529438 (or 529426 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 54.

The square root of 128649789 is about 11342.3890340616. The cubic root of 128649789 is about 504.8197755741.

The spelling of 128649789 in words is "one hundred twenty-eight million, six hundred forty-nine thousand, seven hundred eighty-nine".