133885728 has 72 divisors (see below), whose sum is σ = 387029916. Its totient is φ = 43891200.

The previous prime is 133885711. The next prime is 133885733. The reversal of 133885728 is 827588331.

It can be written as a sum of positive squares in 2 ways, for example, as 132987024 + 898704 = 11532^2 + 948^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13758 + ... + 21378.

Almost surely, 2^133885728 is an apocalyptic number.

133885728 is a gapful number since it is divisible by the number (18) 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 133885728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (193514958).

133885728 is an abundant number, since it is smaller than the sum of its proper divisors (253144188).

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

133885728 is a wasteful number, since it uses less digits than its factorization.

133885728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7698 (or 7687 counting only the distinct ones).

The product of its digits is 322560, while the sum is 45.

The square root of 133885728 is about 11570.9000514221. The cubic root of 133885728 is about 511.5774916063.

The spelling of 133885728 in words is "one hundred thirty-three million, eight hundred eighty-five thousand, seven hundred twenty-eight".