209548009 has 12 divisors (see below), whose sum is σ = 238975632. Its totient is φ = 182210600.

The previous prime is 209547977. The next prime is 209548019. The reversal of 209548009 is 900845902.

It is not a de Polignac number, because 209548009 - 2⁵ = 209547977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (209548019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12187 + ... + 23824.

It is an arithmetic number, because the mean of its divisors is an integer number (19914636).

Almost surely, 2^209548009 is an apocalyptic number.

It is an amenable number.

209548009 is a deficient number, since it is larger than the sum of its proper divisors (29427623).

209548009 is a wasteful number, since it uses less digits than its factorization.

209548009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36068 (or 36045 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 209548009 is about 14475.7731745147. The cubic root of 209548009 is about 593.9654446374.

The spelling of 209548009 in words is "two hundred nine million, five hundred forty-eight thousand, nine".