33728209 has 2 divisors, whose sum is σ = 33728210. Its totient is φ = 33728208.

The previous prime is 33728207. The next prime is 33728213. The reversal of 33728209 is 90282733.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 33640000 + 88209 = 5800^2 + 297^2 .

It is a cyclic number.

It is not a de Polignac number, because 33728209 - 2¹ = 33728207 is a prime.

It is a super-2 number, since 2×33728209² = 2275184164695362, which contains 22 as substring.

Together with 33728207, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (33728203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16864104 + 16864105.

It is an arithmetic number, because the mean of its divisors is an integer number (16864105).

Almost surely, 2^33728209 is an apocalyptic number.

It is an amenable number.

33728209 is a deficient number, since it is larger than the sum of its proper divisors (1).

33728209 is an equidigital number, since it uses as much as digits as its factorization.

33728209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144, while the sum is 34.

The square root of 33728209 is about 5807.5992458158. The cubic root of 33728209 is about 323.0956369952.

The spelling of 33728209 in words is "thirty-three million, seven hundred twenty-eight thousand, two hundred nine".