128817225 has 18 divisors (see below), whose sum is σ = 230726366. Its totient is φ = 68702400.

The previous prime is 128817223. The next prime is 128817229. The reversal of 128817225 is 522718821.

It can be written as a sum of positive squares in 3 ways, for example, as 17424 + 128799801 = 132^2 + 11349^2 .

It is not a de Polignac number, because 128817225 - 2¹ = 128817223 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 128817225.

It is not an unprimeable number, because it can be changed into a prime (128817223) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 286036 + ... + 286485.

Almost surely, 2^128817225 is an apocalyptic number.

128817225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

128817225 is a deficient number, since it is larger than the sum of its proper divisors (101909141).

128817225 is a wasteful number, since it uses less digits than its factorization.

128817225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 572537 (or 572529 counting only the distinct ones).

The product of its digits is 17920, while the sum is 36.

The square root of 128817225 is about 11349.7676187665. The cubic root of 128817225 is about 505.0386860538.

The spelling of 128817225 in words is "one hundred twenty-eight million, eight hundred seventeen thousand, two hundred twenty-five".