33042721 has 2 divisors, whose sum is σ = 33042722. Its totient is φ = 33042720.

The previous prime is 33042703. The next prime is 33042731. The reversal of 33042721 is 12724033.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18181696 + 14861025 = 4264^2 + 3855^2 .

It is a cyclic number.

It is not a de Polignac number, because 33042721 - 2⁵ = 33042689 is a prime.

It is a super-2 number, since 2×33042721² = 2183642822167682, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 33042692 and 33042701.

It is not a weakly prime, because it can be changed into another prime (33042731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16521360 + 16521361.

It is an arithmetic number, because the mean of its divisors is an integer number (16521361).

Almost surely, 2^33042721 is an apocalyptic number.

It is an amenable number.

33042721 is a deficient number, since it is larger than the sum of its proper divisors (1).

33042721 is an equidigital number, since it uses as much as digits as its factorization.

33042721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 22.

The square root of 33042721 is about 5748.2798296534. The cubic root of 33042721 is about 320.8917865199.

Adding to 33042721 its reverse (12724033), we get a palindrome (45766754).

The spelling of 33042721 in words is "thirty-three million, forty-two thousand, seven hundred twenty-one".