33730021 has 8 divisors (see below), whose sum is σ = 36734040. Its totient is φ = 30784512.

The previous prime is 33730007. The next prime is 33730043. The reversal of 33730021 is 12003733.

It can be written as a sum of positive squares in 4 ways, for example, as 2927521 + 30802500 = 1711^2 + 5550^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 33730021 - 2¹¹ = 33727973 is a prime.

It is a super-2 number, since 2×33730021² = 2275428633320882, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33730001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13420 + ... + 15733.

It is an arithmetic number, because the mean of its divisors is an integer number (4591755).

Almost surely, 2^33730021 is an apocalyptic number.

It is an amenable number.

33730021 is a deficient number, since it is larger than the sum of its proper divisors (3004019).

33730021 is a wasteful number, since it uses less digits than its factorization.

33730021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29255.

The product of its (nonzero) digits is 378, while the sum is 19.

The square root of 33730021 is about 5807.7552462204. The cubic root of 33730021 is about 323.1014228426.

Adding to 33730021 its reverse (12003733), we get a palindrome (45733754).

The spelling of 33730021 in words is "thirty-three million, seven hundred thirty thousand, twenty-one".