33121021 has 4 divisors (see below), whose sum is σ = 33165532. Its totient is φ = 33076512.

The previous prime is 33121001. The next prime is 33121027. The reversal of 33121021 is 12012133.

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 18020025 + 15100996 = 4245^2 + 3886^2 .

It is a cyclic number.

It is not a de Polignac number, because 33121021 - 2¹⁷ = 32989949 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 33120992 and 33121010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33121027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21120 + ... + 22633.

It is an arithmetic number, because the mean of its divisors is an integer number (8291383).

Almost surely, 2^33121021 is an apocalyptic number.

It is an amenable number.

33121021 is a deficient number, since it is larger than the sum of its proper divisors (44511).

33121021 is an equidigital number, since it uses as much as digits as its factorization.

33121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44510.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 33121021 is about 5755.0865327986. The cubic root of 33121021 is about 321.1450546695.

Adding to 33121021 its reverse (12012133), we get a palindrome (45133154).

The spelling of 33121021 in words is "thirty-three million, one hundred twenty-one thousand, twenty-one".