33381391 has 2 divisors, whose sum is σ = 33381392. Its totient is φ = 33381390.

The previous prime is 33381377. The next prime is 33381401. The reversal of 33381391 is 19318333.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 33381391 - 2⁷ = 33381263 is a prime.

It is a super-2 number, since 2×33381391² = 2228634530189762, 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 (33381331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16690695 + 16690696.

It is an arithmetic number, because the mean of its divisors is an integer number (16690696).

Almost surely, 2^33381391 is an apocalyptic number.

33381391 is a deficient number, since it is larger than the sum of its proper divisors (1).

33381391 is an equidigital number, since it uses as much as digits as its factorization.

33381391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5832, while the sum is 31.

The square root of 33381391 is about 5777.6631089048. The cubic root of 33381391 is about 321.9843844902.

It can be divided in two parts, 333 and 81391, that multiplied together give a triangular number (27103203 = T₇₃₆₂).

The spelling of 33381391 in words is "thirty-three million, three hundred eighty-one thousand, three hundred ninety-one".