128368505 has 4 divisors (see below), whose sum is σ = 154042212. Its totient is φ = 102694800.

The previous prime is 128368477. The next prime is 128368507. The reversal of 128368505 is 505863821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 505863821 = 1697 ⋅298093.

It can be written as a sum of positive squares in 2 ways, for example, as 67699984 + 60668521 = 8228^2 + 7789^2 .

It is not a de Polignac number, because 128368505 - 2⁶ = 128368441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128368507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12836846 + ... + 12836855.

It is an arithmetic number, because the mean of its divisors is an integer number (38510553).

Almost surely, 2^128368505 is an apocalyptic number.

It is an amenable number.

128368505 is a deficient number, since it is larger than the sum of its proper divisors (25673707).

128368505 is an equidigital number, since it uses as much as digits as its factorization.

128368505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25673706.

The product of its (nonzero) digits is 57600, while the sum is 38.

The square root of 128368505 is about 11329.9825683891. The cubic root of 128368505 is about 504.4515890884.

The spelling of 128368505 in words is "one hundred twenty-eight million, three hundred sixty-eight thousand, five hundred five".