128855720 has 128 divisors (see below), whose sum is σ = 356140800. Its totient is φ = 40974336.

The previous prime is 128855693. The next prime is 128855737. The reversal of 128855720 is 27558821.

128855720 = T₂₆₉₆ + T₂₆₉₇ + ... + T₂₇₃₀.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 281732 + ... + 282188.

It is an arithmetic number, because the mean of its divisors is an integer number (2782350).

Almost surely, 2^128855720 is an apocalyptic number.

128855720 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 128855720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (178070400).

128855720 is an abundant number, since it is smaller than the sum of its proper divisors (227285080).

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

128855720 is a wasteful number, since it uses less digits than its factorization.

128855720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 547 (or 543 counting only the distinct ones).

The product of its (nonzero) digits is 44800, while the sum is 38.

The square root of 128855720 is about 11351.4633417899. The cubic root of 128855720 is about 505.0889886639.

The spelling of 128855720 in words is "one hundred twenty-eight million, eight hundred fifty-five thousand, seven hundred twenty".