1216209 has 12 divisors (see below), whose sum is σ = 1712976. Its totient is φ = 767448.

The previous prime is 1216177. The next prime is 1216213. The reversal of 1216209 is 9026121.

It is not a de Polignac number, because 1216209 - 2⁵ = 1216177 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1216249) 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, 522 + ... + 1644.

It is an arithmetic number, because the mean of its divisors is an integer number (142748).

2^1216209 is an apocalyptic number.

1216209 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

1216209 is a deficient number, since it is larger than the sum of its proper divisors (496767).

1216209 is a wasteful number, since it uses less digits than its factorization.

1216209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1164 (or 1145 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 1216209 is about 1102.8186614308. The cubic root of 1216209 is about 106.7421806857.

The spelling of 1216209 in words is "one million, two hundred sixteen thousand, two hundred nine".