128856667 has 4 divisors (see below), whose sum is σ = 128892960. Its totient is φ = 128820376.

The previous prime is 128856661. The next prime is 128856671. The reversal of 128856667 is 766658821.

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 128856667 - 2³ = 128856659 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 128856667.

It is not an unprimeable number, because it can be changed into a prime (128856661) 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, 12163 + ... + 20140.

It is an arithmetic number, because the mean of its divisors is an integer number (32223240).

Almost surely, 2^128856667 is an apocalyptic number.

128856667 is a deficient number, since it is larger than the sum of its proper divisors (36293).

128856667 is an equidigital number, since it uses as much as digits as its factorization.

128856667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36292.

The product of its digits is 967680, while the sum is 49.

The square root of 128856667 is about 11351.5050543970. The cubic root of 128856667 is about 505.0902260119.

The spelling of 128856667 in words is "one hundred twenty-eight million, eight hundred fifty-six thousand, six hundred sixty-seven".