128728080 has 240 divisors, whose sum is σ = 493562160. Its totient is φ = 29786112.

The previous prime is 128728057. The next prime is 128728081. The reversal of 128728080 is 80827821.

It can be written as a sum of positive squares in 8 ways, for example, as 1218816 + 127509264 = 1104^2 + 11292^2 .

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (128728081) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 158716 + ... + 159524.

It is an arithmetic number, because the mean of its divisors is an integer number (2056509).

Almost surely, 2^128728080 is an apocalyptic number.

128728080 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 128728080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (246781080).

128728080 is an abundant number, since it is smaller than the sum of its proper divisors (364834080).

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

128728080 is a wasteful number, since it uses less digits than its factorization.

128728080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 858 (or 849 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 36.

The square root of 128728080 is about 11345.8397661874. The cubic root of 128728080 is about 504.9221590312.

The spelling of 128728080 in words is "one hundred twenty-eight million, seven hundred twenty-eight thousand, eighty".