128865247 has 6 divisors (see below), whose sum is σ = 149904528. Its totient is φ = 110455884.

The previous prime is 128865227. The next prime is 128865259. The reversal of 128865247 is 742568821.

It is a happy number.

It is not a de Polignac number, because 128865247 - 2¹¹ = 128863199 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128865227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1314903 + ... + 1315000.

It is an arithmetic number, because the mean of its divisors is an integer number (24984088).

Almost surely, 2^128865247 is an apocalyptic number.

128865247 is a deficient number, since it is larger than the sum of its proper divisors (21039281).

128865247 is an equidigital number, since it uses as much as digits as its factorization.

128865247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2629917 (or 2629910 counting only the distinct ones).

The product of its digits is 215040, while the sum is 43.

The square root of 128865247 is about 11351.8829715603. The cubic root of 128865247 is about 505.1014363437.

The spelling of 128865247 in words is "one hundred twenty-eight million, eight hundred sixty-five thousand, two hundred forty-seven".