2085172109 has 2 divisors, whose sum is σ = 2085172110. Its totient is φ = 2085172108.

The previous prime is 2085172097. The next prime is 2085172129. The reversal of 2085172109 is 9012715802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2043311209 + 41860900 = 45203^2 + 6470^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2085172109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2085172129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1042586054 + 1042586055.

It is an arithmetic number, because the mean of its divisors is an integer number (1042586055).

Almost surely, 2^2085172109 is an apocalyptic number.

It is an amenable number.

2085172109 is a deficient number, since it is larger than the sum of its proper divisors (1).

2085172109 is an equidigital number, since it uses as much as digits as its factorization.

2085172109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10080, while the sum is 35.

The square root of 2085172109 is about 45663.6847943746. The cubic root of 2085172109 is about 1277.5580291322.

The spelling of 2085172109 in words is "two billion, eighty-five million, one hundred seventy-two thousand, one hundred nine".