405439 has 2 divisors, whose sum is σ = 405440. Its totient is φ = 405438.

The previous prime is 405437. The next prime is 405473. The reversal of 405439 is 934504.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 405439 - 2¹ = 405437 is a prime.

Together with 405437, it forms a pair of twin primes.

405439 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (405437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202719 + 202720.

It is an arithmetic number, because the mean of its divisors is an integer number (202720).

2⁴⁰⁵⁴³⁹ is an apocalyptic number.

405439 is a deficient number, since it is larger than the sum of its proper divisors (1).

405439 is an equidigital number, since it uses as much as digits as its factorization.

405439 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 405439 is about 636.7409206263. The cubic root of 405439 is about 74.0130850978.

The spelling of 405439 in words is "four hundred five thousand, four hundred thirty-nine".