209938728 has 32 divisors (see below), whose sum is σ = 537055200. Its totient is φ = 68351808.

The previous prime is 209938721. The next prime is 209938793. The reversal of 209938728 is 827839902.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (209938721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 100683 + ... + 102746.

It is an arithmetic number, because the mean of its divisors is an integer number (16782975).

Almost surely, 2^209938728 is an apocalyptic number.

It is an amenable number.

209938728 is an abundant number, since it is smaller than the sum of its proper divisors (327116472).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

209938728 is a wasteful number, since it uses less digits than its factorization.

209938728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203481 (or 203477 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 48.

The square root of 209938728 is about 14489.2625071119. The cubic root of 209938728 is about 594.3343807664.

The spelling of 209938728 in words is "two hundred nine million, nine hundred thirty-eight thousand, seven hundred twenty-eight".