209061216 has 192 divisors, whose sum is σ = 750758400. Its totient is φ = 55116288.

The previous prime is 209061169. The next prime is 209061221. The reversal of 209061216 is 612160902.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 209061216.

It is a congruent number.

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 31 ways as a sum of consecutive naturals, for example, 77295 + ... + 79953.

It is an arithmetic number, because the mean of its divisors is an integer number (3910200).

Almost surely, 2^209061216 is an apocalyptic number.

209061216 is a gapful number since it is divisible by the number (26) 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 209061216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (375379200).

209061216 is an abundant number, since it is smaller than the sum of its proper divisors (541697184).

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

209061216 is a wasteful number, since it uses less digits than its factorization.

209061216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2698 (or 2684 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 209061216 is about 14458.9493394230. The cubic root of 209061216 is about 593.5051485191.

It can be divided in two parts, 20906 and 1216, that added together give a palindrome (22122).

The spelling of 209061216 in words is "two hundred nine million, sixty-one thousand, two hundred sixteen".