128442851 has 4 divisors (see below), whose sum is σ = 129108552. Its totient is φ = 127777152.

The previous prime is 128442829. The next prime is 128442863. The reversal of 128442851 is 158244821.

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 128442851 - 2¹⁰ = 128441827 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128445851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 332561 + ... + 332946.

It is an arithmetic number, because the mean of its divisors is an integer number (32277138).

Almost surely, 2^128442851 is an apocalyptic number.

128442851 is a deficient number, since it is larger than the sum of its proper divisors (665701).

128442851 is an equidigital number, since it uses as much as digits as its factorization.

128442851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 665700.

The product of its digits is 20480, while the sum is 35.

The square root of 128442851 is about 11333.2630340957. The cubic root of 128442851 is about 504.5489564811.

The spelling of 128442851 in words is "one hundred twenty-eight million, four hundred forty-two thousand, eight hundred fifty-one".