128662989 has 64 divisors (see below), whose sum is σ = 227770368.
Its totient is φ = 62726400.
The previous prime is 128662967. The next prime is 128662999. The reversal of 128662989 is 989266821.
It is not a de Polignac number, because 128662989 - 25 = 128662957 is a prime.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (128662999) by changing a digit.
It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 194319 + ... + 194979.
It is an arithmetic number, because the mean of its divisors is an integer number (3558912).
Almost surely, 2128662989 is an apocalyptic number.
It is an amenable number.
128662989 is a deficient number, since it is larger than the sum of its proper divisors (99107379).
128662989 is a wasteful number, since it uses less digits than its factorization.
128662989 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 738.
The product of its digits is 746496, while the sum is 51.
The square root of 128662989 is about 11342.9709071301.
The cubic root of 128662989 is about 504.8370405154.
The spelling of 128662989 in words is "one hundred twenty-eight million, six hundred sixty-two thousand, nine hundred eighty-nine".