406809217 has 4 divisors (see below), whose sum is σ = 412382020. Its totient is φ = 401236416.

The previous prime is 406809131. The next prime is 406809229. The reversal of 406809217 is 712908604.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 300120976 + 106688241 = 17324^2 + 10329^2 .

It is a cyclic number.

It is not a de Polignac number, because 406809217 - 2¹¹ = 406807169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (406809317) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2786292 + ... + 2786437.

It is an arithmetic number, because the mean of its divisors is an integer number (103095505).

Almost surely, 2^406809217 is an apocalyptic number.

It is an amenable number.

406809217 is a deficient number, since it is larger than the sum of its proper divisors (5572803).

406809217 is an equidigital number, since it uses as much as digits as its factorization.

406809217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5572802.

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 406809217 is about 20169.5120664829. The cubic root of 406809217 is about 740.9636927094.

The spelling of 406809217 in words is "four hundred six million, eight hundred nine thousand, two hundred seventeen".