33307728 has 40 divisors (see below), whose sum is σ = 86893248. Its totient is φ = 10993152.

The previous prime is 33307727. The next prime is 33307739. The reversal of 33307728 is 82770333.

It is a happy number.

It is a super-2 number, since 2×33307728² = 2218809489043968, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33307727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1576 + ... + 8312.

Almost surely, 2^33307728 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 33307728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43446624).

33307728 is an abundant number, since it is smaller than the sum of its proper divisors (53585520).

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

33307728 is a wasteful number, since it uses less digits than its factorization.

33307728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6851 (or 6845 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 33.

The square root of 33307728 is about 5771.2847789725. The cubic root of 33307728 is about 321.7473681676.

The spelling of 33307728 in words is "thirty-three million, three hundred seven thousand, seven hundred twenty-eight".