209965380 has 96 divisors (see below), whose sum is σ = 607756800. Its totient is φ = 54120960.

The previous prime is 209965369. The next prime is 209965381. The reversal of 209965380 is 83569902.

It is not an unprimeable number, because it can be changed into a prime (209965381) 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 31 ways as a sum of consecutive naturals, for example, 601446 + ... + 601794.

It is an arithmetic number, because the mean of its divisors is an integer number (6330800).

Almost surely, 2^209965380 is an apocalyptic number.

209965380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 209965380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (303878400).

209965380 is an abundant number, since it is smaller than the sum of its proper divisors (397791420).

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

209965380 is a wasteful number, since it uses less digits than its factorization.

209965380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 669 (or 667 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 42.

The square root of 209965380 is about 14490.1821934716. The cubic root of 209965380 is about 594.3595302149.

The spelling of 209965380 in words is "two hundred nine million, nine hundred sixty-five thousand, three hundred eighty".