33664681 has 2 divisors, whose sum is σ = 33664682. Its totient is φ = 33664680.

The previous prime is 33664669. The next prime is 33664691. The reversal of 33664681 is 18646633.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 32959081 + 705600 = 5741^2 + 840^2 .

It is an emirp because it is prime and its reverse (18646633) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 33664681 - 2¹¹ = 33662633 is a prime.

It is a super-4 number, since 4×33664681⁴ (a number of 31 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 33664681.

It is not a weakly prime, because it can be changed into another prime (33664691) 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, 16832340 + 16832341.

It is an arithmetic number, because the mean of its divisors is an integer number (16832341).

Almost surely, 2^33664681 is an apocalyptic number.

It is an amenable number.

33664681 is a deficient number, since it is larger than the sum of its proper divisors (1).

33664681 is an equidigital number, since it uses as much as digits as its factorization.

33664681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 62208, while the sum is 37.

The square root of 33664681 is about 5802.1272822991. The cubic root of 33664681 is about 322.8926563588.

The spelling of 33664681 in words is "thirty-three million, six hundred sixty-four thousand, six hundred eighty-one".