133621328 has 20 divisors (see below), whose sum is σ = 267819540. Its totient is φ = 64506624.

The previous prime is 133621297. The next prime is 133621331. The reversal of 133621328 is 823126331.

It can be written as a sum of positive squares in 2 ways, for example, as 31449664 + 102171664 = 5608^2 + 10108^2 .

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a self number, because there is not a number n which added to its sum of digits gives 133621328.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 143525 + ... + 144452.

It is an arithmetic number, because the mean of its divisors is an integer number (13390977).

Almost surely, 2^133621328 is an apocalyptic number.

It is an amenable number.

133621328 is an abundant number, since it is smaller than the sum of its proper divisors (134198212).

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

133621328 is a wasteful number, since it uses less digits than its factorization.

133621328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288014 (or 288008 counting only the distinct ones).

The product of its digits is 5184, while the sum is 29.

The square root of 133621328 is about 11559.4691919655. The cubic root of 133621328 is about 511.2405121355.

Adding to 133621328 its reverse (823126331), we get a palindrome (956747659).

The spelling of 133621328 in words is "one hundred thirty-three million, six hundred twenty-one thousand, three hundred twenty-eight".