82218509 has 4 divisors (see below), whose sum is σ = 85053660. Its totient is φ = 79383360.

The previous prime is 82218503. The next prime is 82218517. The reversal of 82218509 is 90581228.

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 19333609 + 62884900 = 4397^2 + 7930^2 .

It is a cyclic number.

It is not a de Polignac number, because 82218509 - 2²⁴ = 65441293 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82218503) 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, 1417532 + ... + 1417589.

It is an arithmetic number, because the mean of its divisors is an integer number (21263415).

Almost surely, 2^82218509 is an apocalyptic number.

It is an amenable number.

82218509 is a deficient number, since it is larger than the sum of its proper divisors (2835151).

82218509 is a wasteful number, since it uses less digits than its factorization.

82218509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2835150.

The product of its (nonzero) digits is 11520, while the sum is 35.

The square root of 82218509 is about 9067.4422523664. The cubic root of 82218509 is about 434.8337039955.

The spelling of 82218509 in words is "eighty-two million, two hundred eighteen thousand, five hundred nine".