10209805 has 4 divisors (see below), whose sum is σ = 12251772. Its totient is φ = 8167840.

The previous prime is 10209803. The next prime is 10209863. The reversal of 10209805 is 50890201.

10209805 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4588164 + 5621641 = 2142^2 + 2371^2 .

It is not a de Polignac number, because 10209805 - 2¹ = 10209803 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 10209805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10209803) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1020976 + ... + 1020985.

It is an arithmetic number, because the mean of its divisors is an integer number (3062943).

Almost surely, 2^10209805 is an apocalyptic number.

It is an amenable number.

10209805 is a deficient number, since it is larger than the sum of its proper divisors (2041967).

10209805 is an equidigital number, since it uses as much as digits as its factorization.

10209805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2041966.

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 10209805 is about 3195.2785481081. The cubic root of 10209805 is about 216.9397568971.

The spelling of 10209805 in words is "ten million, two hundred nine thousand, eight hundred five".