2105852809 has 2 divisors, whose sum is σ = 2105852810. Its totient is φ = 2105852808.

The previous prime is 2105852807. The next prime is 2105852851. The reversal of 2105852809 is 9082585012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1719926784 + 385926025 = 41472^2 + 19645^2 .

It is a cyclic number.

It is not a de Polignac number, because 2105852809 - 2¹ = 2105852807 is a prime.

It is a super-3 number, since 3×2105852809³ (a number of 29 digits) contains 333 as substring.

Together with 2105852807, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (2105852807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1052926404 + 1052926405.

It is an arithmetic number, because the mean of its divisors is an integer number (1052926405).

Almost surely, 2^2105852809 is an apocalyptic number.

It is an amenable number.

2105852809 is a deficient number, since it is larger than the sum of its proper divisors (1).

2105852809 is an equidigital number, since it uses as much as digits as its factorization.

2105852809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 57600, while the sum is 40.

The square root of 2105852809 is about 45889.5718981993. The cubic root of 2105852809 is about 1281.7677416625.

The spelling of 2105852809 in words is "two billion, one hundred five million, eight hundred fifty-two thousand, eight hundred nine".