128520025 has 12 divisors (see below), whose sum is σ = 164861100. Its totient is φ = 99270080.

The previous prime is 128520023. The next prime is 128520061. The reversal of 128520025 is 520025821.

It can be written as a sum of positive squares in 6 ways, for example, as 9339136 + 119180889 = 3056^2 + 10917^2 .

It is not a de Polignac number, because 128520025 - 2¹ = 128520023 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (128520023) 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, 87910 + ... + 89359.

It is an arithmetic number, because the mean of its divisors is an integer number (13738425).

Almost surely, 2^128520025 is an apocalyptic number.

It is an amenable number.

128520025 is a deficient number, since it is larger than the sum of its proper divisors (36341075).

128520025 is a wasteful number, since it uses less digits than its factorization.

128520025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177308 (or 177303 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 25.

The square root of 128520025 is about 11336.6672792316. The cubic root of 128520025 is about 504.6499878345.

Adding to 128520025 its reverse (520025821), we get a palindrome (648545846).

The spelling of 128520025 in words is "one hundred twenty-eight million, five hundred twenty thousand, twenty-five".