209238805 has 16 divisors (see below), whose sum is σ = 269506224. Its totient is φ = 155381760.

The previous prime is 209238803. The next prime is 209238853. The reversal of 209238805 is 508832902.

It can be written as a sum of positive squares in 8 ways, for example, as 8988004 + 200250801 = 2998^2 + 14151^2 .

It is not a de Polignac number, because 209238805 - 2¹ = 209238803 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 (209238803) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10656 + ... + 23065.

It is an arithmetic number, because the mean of its divisors is an integer number (16844139).

Almost surely, 2^209238805 is an apocalyptic number.

It is an amenable number.

209238805 is a deficient number, since it is larger than the sum of its proper divisors (60267419).

209238805 is a wasteful number, since it uses less digits than its factorization.

209238805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33816.

The product of its (nonzero) digits is 34560, while the sum is 37.

The square root of 209238805 is about 14465.0891805063. The cubic root of 209238805 is about 593.6731537850.

The spelling of 209238805 in words is "two hundred nine million, two hundred thirty-eight thousand, eight hundred five".