1216109 has 2 divisors, whose sum is σ = 1216110. Its totient is φ = 1216108.

The previous prime is 1216091. The next prime is 1216123. The reversal of 1216109 is 9016121.

Together with previous prime (1216091) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 850084 + 366025 = 922^2 + 605^2 .

It is an emirp because it is prime and its reverse (9016121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1216109 - 2⁸ = 1215853 is a prime.

It is a Sophie Germain prime.

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1216009) by changing a digit.

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 as a sum of consecutive naturals, namely, 608054 + 608055.

It is an arithmetic number, because the mean of its divisors is an integer number (608055).

2^1216109 is an apocalyptic number.

It is an amenable number.

1216109 is a deficient number, since it is larger than the sum of its proper divisors (1).

1216109 is an equidigital number, since it uses as much as digits as its factorization.

1216109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108, while the sum is 20.

The square root of 1216109 is about 1102.7733221293. The cubic root of 1216109 is about 106.7392550617.

The spelling of 1216109 in words is "one million, two hundred sixteen thousand, one hundred nine".