128819440 has 80 divisors (see below), whose sum is σ = 307346400. Its totient is φ = 50201600.

The previous prime is 128819423. The next prime is 128819441. The reversal of 128819440 is 44918821.

128819440 = 249³ + 250³ + ... + 256³.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 128819440.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128819441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 864486 + ... + 864634.

It is an arithmetic number, because the mean of its divisors is an integer number (3841830).

Almost surely, 2^128819440 is an apocalyptic number.

128819440 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 128819440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (153673200).

128819440 is an abundant number, since it is smaller than the sum of its proper divisors (178526960).

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

128819440 is a wasteful number, since it uses less digits than its factorization.

128819440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 370 (or 364 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 37.

The square root of 128819440 is about 11349.8651974374. The cubic root of 128819440 is about 505.0415807346.

The spelling of 128819440 in words is "one hundred twenty-eight million, eight hundred nineteen thousand, four hundred forty".