128778528 has 24 divisors (see below), whose sum is σ = 338043888. Its totient is φ = 42926144.

The previous prime is 128778509. The next prime is 128778547. The reversal of 128778528 is 825877821.

It is an interprime number because it is at equal distance from previous prime (128778509) and next prime (128778547).

It is a tau number, because it is divible by the number of its divisors (24).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 670626 + ... + 670817.

It is an arithmetic number, because the mean of its divisors is an integer number (14085162).

Almost surely, 2^128778528 is an apocalyptic number.

It is an amenable number.

128778528 is an abundant number, since it is smaller than the sum of its proper divisors (209265360).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

128778528 is a wasteful number, since it uses less digits than its factorization.

128778528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1341456 (or 1341448 counting only the distinct ones).

The product of its digits is 501760, while the sum is 48.

The square root of 128778528 is about 11348.0627421600. The cubic root of 128778528 is about 504.9881093825.

The spelling of 128778528 in words is "one hundred twenty-eight million, seven hundred seventy-eight thousand, five hundred twenty-eight".