133555128 has 128 divisors (see below), whose sum is σ = 408913920. Its totient is φ = 35481600.

The previous prime is 133555127. The next prime is 133555139. The reversal of 133555128 is 821555331.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133555127) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 288225 + ... + 288687.

It is an arithmetic number, because the mean of its divisors is an integer number (3194640).

Almost surely, 2^133555128 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 133555128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (204456960).

133555128 is an abundant number, since it is smaller than the sum of its proper divisors (275358792).

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

133555128 is a wasteful number, since it uses less digits than its factorization.

133555128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 597 (or 593 counting only the distinct ones).

The product of its digits is 18000, while the sum is 33.

The square root of 133555128 is about 11556.6053839352. The cubic root of 133555128 is about 511.1560702452.

The spelling of 133555128 in words is "one hundred thirty-three million, five hundred fifty-five thousand, one hundred twenty-eight".