409391 has 2 divisors, whose sum is σ = 409392. Its totient is φ = 409390.

The previous prime is 409379. The next prime is 409397. The reversal of 409391 is 193904.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 409391 - 2⁶ = 409327 is a prime.

It is a plaindrome in base 12 and base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 409391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (409397) 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, 204695 + 204696.

It is an arithmetic number, because the mean of its divisors is an integer number (204696).

2⁴⁰⁹³⁹¹ is an apocalyptic number.

409391 is a deficient number, since it is larger than the sum of its proper divisors (1).

409391 is an equidigital number, since it uses as much as digits as its factorization.

409391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 972, while the sum is 26.

The square root of 409391 is about 639.8366979160. The cubic root of 409391 is about 74.2527877817.

The spelling of 409391 in words is "four hundred nine thousand, three hundred ninety-one".