405871 has 2 divisors, whose sum is σ = 405872. Its totient is φ = 405870.

The previous prime is 405869. The next prime is 405893. The reversal of 405871 is 178504.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 405871 - 2¹ = 405869 is a prime.

Together with 405869, it forms a pair of twin primes.

405871 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (405071) 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, 202935 + 202936.

It is an arithmetic number, because the mean of its divisors is an integer number (202936).

2⁴⁰⁵⁸⁷¹ is an apocalyptic number.

405871 is a deficient number, since it is larger than the sum of its proper divisors (1).

405871 is an equidigital number, since it uses as much as digits as its factorization.

405871 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1120, while the sum is 25.

The square root of 405871 is about 637.0800577635. The cubic root of 405871 is about 74.0393630364.

The spelling of 405871 in words is "four hundred five thousand, eight hundred seventy-one".