391291 has 2 divisors, whose sum is σ = 391292. Its totient is φ = 391290.

The previous prime is 391283. The next prime is 391301. The reversal of 391291 is 192193.

It is a weak prime.

It is an emirp because it is prime and its reverse (192193) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 391291 - 2³ = 391283 is a prime.

It is not a weakly prime, because it can be changed into another prime (391231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195645 + 195646.

It is an arithmetic number, because the mean of its divisors is an integer number (195646).

2³⁹¹²⁹¹ is an apocalyptic number.

391291 is a deficient number, since it is larger than the sum of its proper divisors (1).

391291 is an equidigital number, since it uses as much as digits as its factorization.

391291 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 486, while the sum is 25.

The square root of 391291 is about 625.5325730927. The cubic root of 391291 is about 73.1419643111.

The spelling of 391291 in words is "three hundred ninety-one thousand, two hundred ninety-one".