209697040 has 80 divisors (see below), whose sum is σ = 589997952. Its totient is φ = 67663872.

The previous prime is 209697031. The next prime is 209697043. The reversal of 209697040 is 40796902.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (209697043) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1494 + ... + 20533.

Almost surely, 2^209697040 is an apocalyptic number.

209697040 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 209697040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (294998976).

209697040 is an abundant number, since it is smaller than the sum of its proper divisors (380300912).

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

209697040 is a wasteful number, since it uses less digits than its factorization.

209697040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22064 (or 22058 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 37.

The square root of 209697040 is about 14480.9198602851. The cubic root of 209697040 is about 594.1062211080.

The spelling of 209697040 in words is "two hundred nine million, six hundred ninety-seven thousand, forty".