128500005 has 8 divisors (see below), whose sum is σ = 205600032. Its totient is φ = 68533328.

The previous prime is 128500003. The next prime is 128500007. The reversal of 128500005 is 500005821.

It is an interprime number because it is at equal distance from previous prime (128500003) and next prime (128500007).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 128500005 - 2¹ = 128500003 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128500003) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4283319 + ... + 4283348.

It is an arithmetic number, because the mean of its divisors is an integer number (25700004).

Almost surely, 2^128500005 is an apocalyptic number.

128500005 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

128500005 is a deficient number, since it is larger than the sum of its proper divisors (77100027).

128500005 is an equidigital number, since it uses as much as digits as its factorization.

128500005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8566675.

The product of its (nonzero) digits is 400, while the sum is 21.

The square root of 128500005 is about 11335.7842692952. The cubic root of 128500005 is about 504.6237827939.

Adding to 128500005 its reverse (500005821), we get a palindrome (628505826).

The spelling of 128500005 in words is "one hundred twenty-eight million, five hundred thousand, five".