82185709 has 2 divisors, whose sum is σ = 82185710. Its totient is φ = 82185708.

The previous prime is 82185707. The next prime is 82185713. The reversal of 82185709 is 90758128.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81540900 + 644809 = 9030^2 + 803^2 .

It is a cyclic number.

It is not a de Polignac number, because 82185709 - 2¹ = 82185707 is a prime.

Together with 82185707, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (82185707) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41092854 + 41092855.

It is an arithmetic number, because the mean of its divisors is an integer number (41092855).

Almost surely, 2^82185709 is an apocalyptic number.

It is an amenable number.

82185709 is a deficient number, since it is larger than the sum of its proper divisors (1).

82185709 is an equidigital number, since it uses as much as digits as its factorization.

82185709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 82185709 is about 9065.6334031330. The cubic root of 82185709 is about 434.7758725627.

The spelling of 82185709 in words is "eighty-two million, one hundred eighty-five thousand, seven hundred nine".