33811381 has 2 divisors, whose sum is σ = 33811382. Its totient is φ = 33811380.

The previous prime is 33811369. The next prime is 33811397. The reversal of 33811381 is 18311833.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30625156 + 3186225 = 5534^2 + 1785^2 .

It is an emirp because it is prime and its reverse (18311833) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 33811381 - 2²¹ = 31714229 is a prime.

It is a super-2 number, since 2×33811381² = 2286418970254322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (33811681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16905690 + 16905691.

It is an arithmetic number, because the mean of its divisors is an integer number (16905691).

Almost surely, 2^33811381 is an apocalyptic number.

It is an amenable number.

33811381 is a deficient number, since it is larger than the sum of its proper divisors (1).

33811381 is an equidigital number, since it uses as much as digits as its factorization.

33811381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 28.

The square root of 33811381 is about 5814.7554548751. The cubic root of 33811381 is about 323.3609979754.

The spelling of 33811381 in words is "thirty-three million, eight hundred eleven thousand, three hundred eighty-one".