405217 has 8 divisors (see below), whose sum is σ = 426600. Its totient is φ = 384384.

The previous prime is 405211. The next prime is 405221. The reversal of 405217 is 712504.

It can be written as a sum of positive squares in 4 ways, for example, as 7056 + 398161 = 84^2 + 631^2 .

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 405217 - 2⁷ = 405089 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 405194 and 405203.

It is not an unprimeable number, because it can be changed into a prime (405211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2503 + ... + 2659.

It is an arithmetic number, because the mean of its divisors is an integer number (53325).

2⁴⁰⁵²¹⁷ is an apocalyptic number.

It is an amenable number.

405217 is a deficient number, since it is larger than the sum of its proper divisors (21383).

405217 is a wasteful number, since it uses less digits than its factorization.

405217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 275.

The product of its (nonzero) digits is 280, while the sum is 19.

The square root of 405217 is about 636.5665715383. The cubic root of 405217 is about 73.9995738958. Note that the first 3 decimals are identical.

The spelling of 405217 in words is "four hundred five thousand, two hundred seventeen".