2085172909 has 2 divisors, whose sum is σ = 2085172910. Its totient is φ = 2085172908.

The previous prime is 2085172889. The next prime is 2085172937. The reversal of 2085172909 is 9092715802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1834837225 + 250335684 = 42835^2 + 15822^2 .

It is a cyclic number.

It is not a de Polignac number, because 2085172909 - 2¹³ = 2085164717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2085172109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1042586454 + 1042586455.

It is an arithmetic number, because the mean of its divisors is an integer number (1042586455).

Almost surely, 2^2085172909 is an apocalyptic number.

It is an amenable number.

2085172909 is a deficient number, since it is larger than the sum of its proper divisors (1).

2085172909 is an equidigital number, since it uses as much as digits as its factorization.

2085172909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90720, while the sum is 43.

The square root of 2085172909 is about 45663.6935540698. The cubic root of 2085172909 is about 1277.5581925154.

The spelling of 2085172909 in words is "two billion, eighty-five million, one hundred seventy-two thousand, nine hundred nine".