33663221 has 2 divisors, whose sum is σ = 33663222. Its totient is φ = 33663220.

The previous prime is 33663209. The next prime is 33663239. The reversal of 33663221 is 12236633.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31516996 + 2146225 = 5614^2 + 1465^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-33663221 is a prime.

It is a super-2 number, since 2×33663221² = 2266424896189682, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (33663251) 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 as a sum of consecutive naturals, namely, 16831610 + 16831611.

It is an arithmetic number, because the mean of its divisors is an integer number (16831611).

Almost surely, 2^33663221 is an apocalyptic number.

It is an amenable number.

33663221 is a deficient number, since it is larger than the sum of its proper divisors (1).

33663221 is an equidigital number, since it uses as much as digits as its factorization.

33663221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3888, while the sum is 26.

The square root of 33663221 is about 5802.0014650119. The cubic root of 33663221 is about 322.8879884588.

Adding to 33663221 its reverse (12236633), we get a palindrome (45899854).

The spelling of 33663221 in words is "thirty-three million, six hundred sixty-three thousand, two hundred twenty-one".