209640930 has 32 divisors (see below), whose sum is σ = 503798400. Its totient is φ = 55830912.

The previous prime is 209640911. The next prime is 209640931. The reversal of 209640930 is 39046902.

It is a junction number, because it is equal to n+sod(n) for n = 209640891 and 209640900.

It is not an unprimeable number, because it can be changed into a prime (209640931) 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, 21006 + ... + 29334.

It is an arithmetic number, because the mean of its divisors is an integer number (15743700).

Almost surely, 2^209640930 is an apocalyptic number.

209640930 is an abundant number, since it is smaller than the sum of its proper divisors (294157470).

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

209640930 is a wasteful number, since it uses less digits than its factorization.

209640930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9178.

The product of its (nonzero) digits is 11664, while the sum is 33.

The square root of 209640930 is about 14478.9823537430. The cubic root of 209640930 is about 594.0532267600.

The spelling of 209640930 in words is "two hundred nine million, six hundred forty thousand, nine hundred thirty".