128000005 has 12 divisors (see below), whose sum is σ = 178677900. Its totient is φ = 87771264.

The previous prime is 128000003. The next prime is 128000009. The reversal of 128000005 is 500000821.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 21538881 + 106461124 = 4641^2 + 10318^2 .

It is not a de Polignac number, because 128000005 - 2¹ = 128000003 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128000003) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 260980 + ... + 261469.

It is an arithmetic number, because the mean of its divisors is an integer number (14889825).

Almost surely, 2^128000005 is an apocalyptic number.

It is an amenable number.

128000005 is a deficient number, since it is larger than the sum of its proper divisors (50677895).

128000005 is an equidigital number, since it uses as much as digits as its factorization.

128000005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 522468 (or 522461 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 128000005 is about 11313.7087199556. The cubic root of 128000005 is about 503.9684265200.

Adding to 128000005 its reverse (500000821), we get a palindrome (628000826).

It can be divided in two parts, 12800000 and 5, that multiplied together give a 6-th power (64000000 = 20⁶).

The spelling of 128000005 in words is "one hundred twenty-eight million, five", and thus it is an aban number.