128682889 has 4 divisors (see below), whose sum is σ = 133120260. Its totient is φ = 124245520.

The previous prime is 128682859. The next prime is 128682899. The reversal of 128682889 is 988286821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 988286821 = 23557 ⋅41953.

It can be written as a sum of positive squares in 2 ways, for example, as 76265289 + 52417600 = 8733^2 + 7240^2 .

It is a cyclic number.

It is not a de Polignac number, because 128682889 - 2⁷ = 128682761 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128682859) 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, 2218642 + ... + 2218699.

It is an arithmetic number, because the mean of its divisors is an integer number (33280065).

Almost surely, 2^128682889 is an apocalyptic number.

It is an amenable number.

128682889 is a deficient number, since it is larger than the sum of its proper divisors (4437371).

128682889 is an equidigital number, since it uses as much as digits as its factorization.

128682889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4437370.

The product of its digits is 884736, while the sum is 52.

The square root of 128682889 is about 11343.8480684466. The cubic root of 128682889 is about 504.8630664904.

The spelling of 128682889 in words is "one hundred twenty-eight million, six hundred eighty-two thousand, eight hundred eighty-nine".