128243165 has 4 divisors (see below), whose sum is σ = 153891804. Its totient is φ = 102594528.

The previous prime is 128243161. The next prime is 128243197. The reversal of 128243165 is 561342821.

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

It can be written as a sum of positive squares in 2 ways, for example, as 22934521 + 105308644 = 4789^2 + 10262^2 .

It is a cyclic number.

It is not a de Polignac number, because 128243165 - 2² = 128243161 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128243161) 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, 12824312 + ... + 12824321.

It is an arithmetic number, because the mean of its divisors is an integer number (38472951).

Almost surely, 2^128243165 is an apocalyptic number.

It is an amenable number.

128243165 is a deficient number, since it is larger than the sum of its proper divisors (25648639).

128243165 is an equidigital number, since it uses as much as digits as its factorization.

128243165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25648638.

The product of its digits is 11520, while the sum is 32.

The square root of 128243165 is about 11324.4498762633. The cubic root of 128243165 is about 504.2873521465.

Adding to 128243165 its reverse (561342821), we get a palindrome (689585986).

The spelling of 128243165 in words is "one hundred twenty-eight million, two hundred forty-three thousand, one hundred sixty-five".