209149770 has 16 divisors (see below), whose sum is σ = 501959520. Its totient is φ = 55773264.

The previous prime is 209149763. The next prime is 209149771. The reversal of 209149770 is 77941902.

It is not an unprimeable number, because it can be changed into a prime (209149771) 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 7 ways as a sum of consecutive naturals, for example, 3485800 + ... + 3485859.

It is an arithmetic number, because the mean of its divisors is an integer number (31372470).

Almost surely, 2^209149770 is an apocalyptic number.

209149770 is an abundant number, since it is smaller than the sum of its proper divisors (292809750).

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

209149770 is a wasteful number, since it uses less digits than its factorization.

209149770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6971669.

The product of its (nonzero) digits is 31752, while the sum is 39.

The square root of 209149770 is about 14462.0112709125. The cubic root of 209149770 is about 593.5889355185.

The spelling of 209149770 in words is "two hundred nine million, one hundred forty-nine thousand, seven hundred seventy".