128787205 has 4 divisors (see below), whose sum is σ = 154544652. Its totient is φ = 103029760.

The previous prime is 128787203. The next prime is 128787229. The reversal of 128787205 is 502787821.

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 30658369 + 98128836 = 5537^2 + 9906^2 .

It is not a de Polignac number, because 128787205 - 2¹ = 128787203 is a prime.

It is a super-2 number, since 2×128787205² = 33172288343424050, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128787203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12878716 + ... + 12878725.

It is an arithmetic number, because the mean of its divisors is an integer number (38636163).

Almost surely, 2^128787205 is an apocalyptic number.

It is an amenable number.

128787205 is a deficient number, since it is larger than the sum of its proper divisors (25757447).

128787205 is an equidigital number, since it uses as much as digits as its factorization.

128787205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25757446.

The product of its (nonzero) digits is 62720, while the sum is 40.

The square root of 128787205 is about 11348.4450476706. The cubic root of 128787205 is about 504.9994510336. Note that the first 3 decimals are identical.

The spelling of 128787205 in words is "one hundred twenty-eight million, seven hundred eighty-seven thousand, two hundred five".