128279889 has 32 divisors (see below), whose sum is σ = 196058880. Its totient is φ = 82857600.

The previous prime is 128279869. The next prime is 128279927. The reversal of 128279889 is 988972821.

It is not a de Polignac number, because 128279889 - 2⁸ = 128279633 is a prime.

It is not an unprimeable number, because it can be changed into a prime (128279819) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 116389 + ... + 117485.

It is an arithmetic number, because the mean of its divisors is an integer number (6126840).

Almost surely, 2^128279889 is an apocalyptic number.

It is an amenable number.

128279889 is a deficient number, since it is larger than the sum of its proper divisors (67778991).

128279889 is a wasteful number, since it uses less digits than its factorization.

128279889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1238 (or 1232 counting only the distinct ones).

The product of its digits is 1161216, while the sum is 54.

The square root of 128279889 is about 11326.0712076165. The cubic root of 128279889 is about 504.3354838377.

The spelling of 128279889 in words is "one hundred twenty-eight million, two hundred seventy-nine thousand, eight hundred eighty-nine".