128966609 has 4 divisors (see below), whose sum is σ = 130218816. Its totient is φ = 127714404.

The previous prime is 128966599. The next prime is 128966633. The reversal of 128966609 is 906669821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 128966609 - 2⁸ = 128966353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128966639) 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, 625949 + ... + 626154.

It is an arithmetic number, because the mean of its divisors is an integer number (32554704).

Almost surely, 2^128966609 is an apocalyptic number.

It is an amenable number.

128966609 is a deficient number, since it is larger than the sum of its proper divisors (1252207).

128966609 is a wasteful number, since it uses less digits than its factorization.

128966609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1252206.

The product of its (nonzero) digits is 279936, while the sum is 47.

The square root of 128966609 is about 11356.3466396548. The cubic root of 128966609 is about 505.2338347861.

The spelling of 128966609 in words is "one hundred twenty-eight million, nine hundred sixty-six thousand, six hundred nine".