846405809 has 4 divisors (see below), whose sum is σ = 896194404. Its totient is φ = 796617216.

The previous prime is 846405797. The next prime is 846405817. The reversal of 846405809 is 908504648.

It is a happy number.

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 732514225 + 113891584 = 27065^2 + 10672^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-846405809 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 846405809.

It is not an unprimeable number, because it can be changed into a prime (846425809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24894272 + ... + 24894305.

It is an arithmetic number, because the mean of its divisors is an integer number (224048601).

Almost surely, 2^846405809 is an apocalyptic number.

It is an amenable number.

846405809 is a deficient number, since it is larger than the sum of its proper divisors (49788595).

846405809 is a wasteful number, since it uses less digits than its factorization.

846405809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49788594.

The product of its (nonzero) digits is 276480, while the sum is 44.

The square root of 846405809 is about 29093.0543085459. The cubic root of 846405809 is about 945.9311889095.

The spelling of 846405809 in words is "eight hundred forty-six million, four hundred five thousand, eight hundred nine".