405679 has 2 divisors, whose sum is σ = 405680. Its totient is φ = 405678.

The previous prime is 405677. The next prime is 405683. The reversal of 405679 is 976504.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 405679 - 2¹ = 405677 is a prime.

Together with 405677, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 405679.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (405677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202839 + 202840.

It is an arithmetic number, because the mean of its divisors is an integer number (202840).

2⁴⁰⁵⁶⁷⁹ is an apocalyptic number.

405679 is a deficient number, since it is larger than the sum of its proper divisors (1).

405679 is an equidigital number, since it uses as much as digits as its factorization.

405679 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7560, while the sum is 31.

The square root of 405679 is about 636.9293524403. The cubic root of 405679 is about 74.0276862557.

The spelling of 405679 in words is "four hundred five thousand, six hundred seventy-nine".