33391381 has 2 divisors, whose sum is σ = 33391382. Its totient is φ = 33391380.

The previous prime is 33391373. The next prime is 33391399. The reversal of 33391381 is 18319333.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30802500 + 2588881 = 5550^2 + 1609^2 .

It is a cyclic number.

It is not a de Polignac number, because 33391381 - 2³ = 33391373 is a prime.

It is a super-2 number, since 2×33391381² = 2229968650174322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (33391181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16695690 + 16695691.

It is an arithmetic number, because the mean of its divisors is an integer number (16695691).

Almost surely, 2^33391381 is an apocalyptic number.

It is an amenable number.

33391381 is a deficient number, since it is larger than the sum of its proper divisors (1).

33391381 is an equidigital number, since it uses as much as digits as its factorization.

33391381 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 33391381 is about 5778.5275806212. The cubic root of 33391381 is about 322.0165012183.

The spelling of 33391381 in words is "thirty-three million, three hundred ninety-one thousand, three hundred eighty-one".