128505550 has 96 divisors (see below), whose sum is σ = 272527200. Its totient is φ = 44789760.

The previous prime is 128505539. The next prime is 128505557. The reversal of 128505550 is 55505821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128505557) 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, 1178896 + ... + 1179004.

It is an arithmetic number, because the mean of its divisors is an integer number (2838825).

Almost surely, 2^128505550 is an apocalyptic number.

128505550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

128505550 is an abundant number, since it is smaller than the sum of its proper divisors (144021650).

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

128505550 is a wasteful number, since it uses less digits than its factorization.

128505550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230 (or 225 counting only the distinct ones).

The product of its (nonzero) digits is 10000, while the sum is 31.

The square root of 128505550 is about 11336.0288461171. The cubic root of 128505550 is about 504.6310411559.

The spelling of 128505550 in words is "one hundred twenty-eight million, five hundred five thousand, five hundred fifty".