2105708509 has 4 divisors (see below), whose sum is σ = 2107356160. Its totient is φ = 2104060860.

The previous prime is 2105708503. The next prime is 2105708513. The reversal of 2105708509 is 9058075012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2105708509 - 2⁹ = 2105707997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2105708503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 821907 + ... + 824464.

It is an arithmetic number, because the mean of its divisors is an integer number (526839040).

Almost surely, 2^2105708509 is an apocalyptic number.

It is an amenable number.

2105708509 is a deficient number, since it is larger than the sum of its proper divisors (1647651).

2105708509 is a wasteful number, since it uses less digits than its factorization.

2105708509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1647650.

The product of its (nonzero) digits is 25200, while the sum is 37.

The square root of 2105708509 is about 45887.9996186367. Note that the first 3 decimals coincide. The cubic root of 2105708509 is about 1281.7384640053.

The spelling of 2105708509 in words is "two billion, one hundred five million, seven hundred eight thousand, five hundred nine".