33981728 has 48 divisors (see below), whose sum is σ = 76839840. Its totient is φ = 14630400.

The previous prime is 33981721. The next prime is 33981733. The reversal of 33981728 is 82718933.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33981721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4148 + ... + 9228.

It is an arithmetic number, because the mean of its divisors is an integer number (1600830).

Almost surely, 2^33981728 is an apocalyptic number.

33981728 is a gapful number since it is divisible by the number (38) 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 33981728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38419920).

33981728 is an abundant number, since it is smaller than the sum of its proper divisors (42858112).

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

33981728 is a wasteful number, since it uses less digits than its factorization.

33981728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5121 (or 5113 counting only the distinct ones).

The product of its digits is 72576, while the sum is 41.

The square root of 33981728 is about 5829.3848732092. The cubic root of 33981728 is about 323.9031362122.

The spelling of 33981728 in words is "thirty-three million, nine hundred eighty-one thousand, seven hundred twenty-eight".