128817925 has 24 divisors (see below), whose sum is σ = 170861832. Its totient is φ = 96000000.

The previous prime is 128817919. The next prime is 128817943. The reversal of 128817925 is 529718821.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 720801 + 128097124 = 849^2 + 11318^2 .

It is not a de Polignac number, because 128817925 - 2¹⁵ = 128785157 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 41425 + ... + 44425.

It is an arithmetic number, because the mean of its divisors is an integer number (7119243).

Almost surely, 2^128817925 is an apocalyptic number.

It is an amenable number.

128817925 is a deficient number, since it is larger than the sum of its proper divisors (42043907).

128817925 is a wasteful number, since it uses less digits than its factorization.

128817925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3129 (or 3124 counting only the distinct ones).

The product of its digits is 80640, while the sum is 43.

The square root of 128817925 is about 11349.7984563604. The cubic root of 128817925 is about 505.0396008549.

The spelling of 128817925 in words is "one hundred twenty-eight million, eight hundred seventeen thousand, nine hundred twenty-five".