209916 has 72 divisors (see below), whose sum is σ = 655200. Its totient is φ = 56448.

The previous prime is 209887. The next prime is 209917. The reversal of 209916 is 619902.

209916 = 20³ + 21³ + ... + 31³.

It is a happy number.

It is a zygodrome in base 2.

It is a self number, because there is not a number n which added to its sum of digits gives 209916.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 209916.

It is not an unprimeable number, because it can be changed into a prime (209917) by changing a digit.

209916 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12340 + ... + 12356.

It is an arithmetic number, because the mean of its divisors is an integer number (9100).

2²⁰⁹⁹¹⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 209916, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (327600).

209916 is an abundant number, since it is smaller than the sum of its proper divisors (445284).

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

209916 is a wasteful number, since it uses less digits than its factorization.

209916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48 (or 29 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 209916 is about 458.1659088147. The cubic root of 209916 is about 59.4312932414.

The spelling of 209916 in words is "two hundred nine thousand, nine hundred sixteen".