82106209 has 4 divisors (see below), whose sum is σ = 86936004. Its totient is φ = 77276416.

The previous prime is 82106207. The next prime is 82106237. The reversal of 82106209 is 90260128.

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 33315984 + 48790225 = 5772^2 + 6985^2 .

It is a cyclic number.

It is not a de Polignac number, because 82106209 - 2¹ = 82106207 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (82106207) 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, 2414872 + ... + 2414905.

It is an arithmetic number, because the mean of its divisors is an integer number (21734001).

Almost surely, 2^82106209 is an apocalyptic number.

It is an amenable number.

82106209 is a deficient number, since it is larger than the sum of its proper divisors (4829795).

82106209 is a wasteful number, since it uses less digits than its factorization.

82106209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4829794.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 82106209 is about 9061.2476513999. The cubic root of 82106209 is about 434.6356379918.

The spelling of 82106209 in words is "eighty-two million, one hundred six thousand, two hundred nine".