209149938 has 40 divisors (see below), whose sum is σ = 480096540. Its totient is φ = 68014080.

The previous prime is 209149931. The next prime is 209149939. The reversal of 209149938 is 839941902.

209149938 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 197880489 + 11269449 = 14067^2 + 3357^2 .

It is a junction number, because it is equal to n+sod(n) for n = 209149893 and 209149902.

It is not an unprimeable number, because it can be changed into a prime (209149931) 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 19 ways as a sum of consecutive naturals, for example, 9103 + ... + 22386.

Almost surely, 2^209149938 is an apocalyptic number.

209149938 is an abundant number, since it is smaller than the sum of its proper divisors (270946602).

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

209149938 is a wasteful number, since it uses less digits than its factorization.

209149938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31544 (or 31535 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 45.

The square root of 209149938 is about 14462.0170792321. The cubic root of 209149938 is about 593.5890944523.

The spelling of 209149938 in words is "two hundred nine million, one hundred forty-nine thousand, nine hundred thirty-eight".