128889667 has 4 divisors (see below), whose sum is σ = 128929720. Its totient is φ = 128849616.

The previous prime is 128889653. The next prime is 128889679. The reversal of 128889667 is 766988821.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 128889667 - 2¹⁹ = 128365379 is a prime.

It is a super-2 number, since 2×128889667² = 33225092518741778, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128889617) 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, 14733 + ... + 21790.

It is an arithmetic number, because the mean of its divisors is an integer number (32232430).

Almost surely, 2^128889667 is an apocalyptic number.

128889667 is a deficient number, since it is larger than the sum of its proper divisors (40053).

128889667 is an equidigital number, since it uses as much as digits as its factorization.

128889667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40052.

The product of its digits is 2322432, while the sum is 55.

The square root of 128889667 is about 11352.9585130925. The cubic root of 128889667 is about 505.1333399492.

The spelling of 128889667 in words is "one hundred twenty-eight million, eight hundred eighty-nine thousand, six hundred sixty-seven".