8420009 has 4 divisors (see below), whose sum is σ = 9067716. Its totient is φ = 7772304.

The previous prime is 8419993. The next prime is 8420029. The reversal of 8420009 is 9000248.

8420009 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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 5161984 + 3258025 = 2272^2 + 1805^2 .

It is a cyclic number.

It is not a de Polignac number, because 8420009 - 2⁴ = 8419993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8420029) 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, 323834 + ... + 323859.

It is an arithmetic number, because the mean of its divisors is an integer number (2266929).

Almost surely, 2^8420009 is an apocalyptic number.

It is an amenable number.

8420009 is a deficient number, since it is larger than the sum of its proper divisors (647707).

8420009 is a wasteful number, since it uses less digits than its factorization.

8420009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 647706.

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 8420009 is about 2901.7251765114. The cubic root of 8420009 is about 203.4405487300.

The spelling of 8420009 in words is "eight million, four hundred twenty thousand, nine".