405565 has 8 divisors (see below), whose sum is σ = 503640. Its totient is φ = 313152.

The previous prime is 405553. The next prime is 405577. The reversal of 405565 is 565504.

It is an interprime number because it is at equal distance from previous prime (405553) and next prime (405577).

It can be written as a sum of positive squares in 4 ways, for example, as 79524 + 326041 = 282^2 + 571^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 405565 - 2⁷ = 405437 is a prime.

405565 is a lucky number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1254 + ... + 1543.

It is an arithmetic number, because the mean of its divisors is an integer number (62955).

2⁴⁰⁵⁵⁶⁵ is an apocalyptic number.

It is an amenable number.

405565 is a deficient number, since it is larger than the sum of its proper divisors (98075).

405565 is a wasteful number, since it uses less digits than its factorization.

405565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2831.

The product of its (nonzero) digits is 3000, while the sum is 25.

The square root of 405565 is about 636.8398542805. The cubic root of 405565 is about 74.0207514240.

The spelling of 405565 in words is "four hundred five thousand, five hundred sixty-five".