128135808 has 48 divisors (see below), whose sum is σ = 368727450. Its totient is φ = 42711552.

The previous prime is 128135797. The next prime is 128135837. The reversal of 128135808 is 808531821.

It can be written as a sum of positive squares in only one way, i.e., 107993664 + 20142144 = 10392^2 + 4488^2 .

It is a tau number, because it is divible by the number of its divisors (48).

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 54463 + ... + 56766.

Almost surely, 2^128135808 is an apocalyptic number.

128135808 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

128135808 is an abundant number, since it is smaller than the sum of its proper divisors (240591642).

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

128135808 is a wasteful number, since it uses less digits than its factorization.

128135808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111249 (or 111234 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 36.

The square root of 128135808 is about 11319.7088301776. The cubic root of 128135808 is about 504.1465937898.

The spelling of 128135808 in words is "one hundred twenty-eight million, one hundred thirty-five thousand, eight hundred eight".