128778240 has 136 divisors (see below), whose sum is σ = 415232928. Its totient is φ = 34078720.

The previous prime is 128778227. The next prime is 128778271. The reversal of 128778240 is 42877821.

It is a nialpdrome in base 8.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 982975 + ... + 983105.

Almost surely, 2^128778240 is an apocalyptic number.

128778240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128778240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (207616464).

128778240 is an abundant number, since it is smaller than the sum of its proper divisors (286454688).

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

128778240 is an frugal number, since it uses more digits than its factorization.

128778240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171 (or 141 counting only the distinct ones).

The product of its (nonzero) digits is 50176, while the sum is 39.

The square root of 128778240 is about 11348.0500527624. The cubic root of 128778240 is about 504.9877329308.

The spelling of 128778240 in words is "one hundred twenty-eight million, seven hundred seventy-eight thousand, two hundred forty".