33806921 has 4 divisors (see below), whose sum is σ = 33825744. Its totient is φ = 33788100.

The previous prime is 33806911. The next prime is 33806923. The reversal of 33806921 is 12960833.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12960833 = 557 ⋅23269.

It is a cyclic number.

It is not a de Polignac number, because 33806921 - 2¹⁰ = 33805897 is a prime.

It is a super-2 number, since 2×33806921² = 2285815815000482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (33806923) by changing a digit.

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

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6395 + ... + 10416.

It is an arithmetic number, because the mean of its divisors is an integer number (8456436).

Almost surely, 2^33806921 is an apocalyptic number.

It is an amenable number.

33806921 is a deficient number, since it is larger than the sum of its proper divisors (18823).

33806921 is a wasteful number, since it uses less digits than its factorization.

33806921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18822.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 33806921 is about 5814.3719351276. The cubic root of 33806921 is about 323.3467793560.

It can be divided in two parts, 3380 and 6921, that added together give a palindrome (10301).

The spelling of 33806921 in words is "thirty-three million, eight hundred six thousand, nine hundred twenty-one".