8213409 has 12 divisors (see below), whose sum is σ = 12273300. Its totient is φ = 5286624.

The previous prime is 8213399. The next prime is 8213411. The reversal of 8213409 is 9043128.

It can be written as a sum of positive squares in 2 ways, for example, as 4100625 + 4112784 = 2025^2 + 2028^2 .

It is not a de Polignac number, because 8213409 - 2¹¹ = 8211361 is a prime.

It is not an unprimeable number, because it can be changed into a prime (8213459) 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 11 ways as a sum of consecutive naturals, for example, 15474 + ... + 15995.

It is an arithmetic number, because the mean of its divisors is an integer number (1022775).

Almost surely, 2^8213409 is an apocalyptic number.

It is an amenable number.

8213409 is a deficient number, since it is larger than the sum of its proper divisors (4059891).

8213409 is a wasteful number, since it uses less digits than its factorization.

8213409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31504 (or 31501 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 8213409 is about 2865.9045692416. The cubic root of 8213409 is about 201.7628249242.

The spelling of 8213409 in words is "eight million, two hundred thirteen thousand, four hundred nine".