209309040 has 60 divisors (see below), whose sum is σ = 702931944. Its totient is φ = 55815552.

The previous prime is 209309033. The next prime is 209309041. The reversal of 209309040 is 40903902.

It is a tau number, because it is divible by the number of its divisors (60).

It is a junction number, because it is equal to n+sod(n) for n = 209308995 and 209309013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209309041) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 144634 + ... + 146073.

Almost surely, 2^209309040 is an apocalyptic number.

209309040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

209309040 is an abundant number, since it is smaller than the sum of its proper divisors (493622904).

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

209309040 is a wasteful number, since it uses less digits than its factorization.

209309040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290726 (or 290717 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 27.

The square root of 209309040 is about 14467.5167184973. The cubic root of 209309040 is about 593.7395722638.

The spelling of 209309040 in words is "two hundred nine million, three hundred nine thousand, forty".