33428209 has 4 divisors (see below), whose sum is σ = 33443316. Its totient is φ = 33413104.

The previous prime is 33428189. The next prime is 33428251. The reversal of 33428209 is 90282433.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11833600 + 21594609 = 3440^2 + 4647^2 .

It is a cyclic number.

It is not a de Polignac number, because 33428209 - 2⁷ = 33428081 is a prime.

It is a super-2 number, since 2×33428209² = 2234890313895362, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (33428009) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3514 + ... + 8899.

It is an arithmetic number, because the mean of its divisors is an integer number (8360829).

Almost surely, 2^33428209 is an apocalyptic number.

It is an amenable number.

33428209 is a deficient number, since it is larger than the sum of its proper divisors (15107).

33428209 is a wasteful number, since it uses less digits than its factorization.

33428209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15106.

The product of its (nonzero) digits is 10368, while the sum is 31.

The square root of 33428209 is about 5781.7133273797. The cubic root of 33428209 is about 322.1348437975.

The spelling of 33428209 in words is "thirty-three million, four hundred twenty-eight thousand, two hundred nine".