209343040 has 56 divisors (see below), whose sum is σ = 511999992. Its totient is φ = 81469440.

The previous prime is 209343037. The next prime is 209343053. The reversal of 209343040 is 40343902.

It can be written as a sum of positive squares in 4 ways, for example, as 36578304 + 172764736 = 6048^2 + 13144^2 .

It is a junction number, because it is equal to n+sod(n) for n = 209342996 and 209343014.

It is an unprimeable number.

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, 3000 + ... + 20680.

It is an arithmetic number, because the mean of its divisors is an integer number (9142857).

Almost surely, 2^209343040 is an apocalyptic number.

209343040 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 209343040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (255999996).

209343040 is an abundant number, since it is smaller than the sum of its proper divisors (302656952).

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

209343040 is a wasteful number, since it uses less digits than its factorization.

209343040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17735 (or 17725 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 25.

The square root of 209343040 is about 14468.6917169452. The cubic root of 209343040 is about 593.7717193902.

Adding to 209343040 its reverse (40343902), we get a palindrome (249686942).

The spelling of 209343040 in words is "two hundred nine million, three hundred forty-three thousand, forty".