33409381 has 2 divisors, whose sum is σ = 33409382. Its totient is φ = 33409380.

The previous prime is 33409379. The next prime is 33409393. The reversal of 33409381 is 18390433.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20557156 + 12852225 = 4534^2 + 3585^2 .

It is an emirp because it is prime and its reverse (18390433) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 33409381 - 2¹ = 33409379 is a prime.

It is a super-2 number, since 2×33409381² = 2232373477606322, which contains 22 as substring.

Together with 33409379, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (33409331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16704690 + 16704691.

It is an arithmetic number, because the mean of its divisors is an integer number (16704691).

Almost surely, 2^33409381 is an apocalyptic number.

It is an amenable number.

33409381 is a deficient number, since it is larger than the sum of its proper divisors (1).

33409381 is an equidigital number, since it uses as much as digits as its factorization.

33409381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 31.

The square root of 33409381 is about 5780.0848609687. The cubic root of 33409381 is about 322.0743530316.

It can be divided in two parts, 3340 and 9381, that added together give a palindrome (12721).

The spelling of 33409381 in words is "thirty-three million, four hundred nine thousand, three hundred eighty-one".