438391 has 2 divisors, whose sum is σ = 438392. Its totient is φ = 438390.

The previous prime is 438377. The next prime is 438401. The reversal of 438391 is 193834.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 438391 - 2¹¹ = 436343 is a prime.

438391 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (438301) 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, 219195 + 219196.

It is an arithmetic number, because the mean of its divisors is an integer number (219196).

2⁴³⁸³⁹¹ is an apocalyptic number.

438391 is a deficient number, since it is larger than the sum of its proper divisors (1).

438391 is an equidigital number, since it uses as much as digits as its factorization.

438391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2592, while the sum is 28.

The square root of 438391 is about 662.1110178814. Note that the first 3 decimals coincide. The cubic root of 438391 is about 75.9662246042.

The spelling of 438391 in words is "four hundred thirty-eight thousand, three hundred ninety-one".