1220209 has 4 divisors (see below), whose sum is σ = 1292004. Its totient is φ = 1148416.

The previous prime is 1220203. The next prime is 1220239. The reversal of 1220209 is 9020221.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9020221 = 7 ⋅1288603.

It can be written as a sum of positive squares in 2 ways, for example, as 893025 + 327184 = 945^2 + 572^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220209 - 2¹³ = 1212017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1220192 and 1220201.

It is not an unprimeable number, because it can be changed into a prime (1220203) 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 in 3 ways as a sum of consecutive naturals, for example, 35872 + ... + 35905.

It is an arithmetic number, because the mean of its divisors is an integer number (323001).

2^1220209 is an apocalyptic number.

It is an amenable number.

1220209 is a deficient number, since it is larger than the sum of its proper divisors (71795).

1220209 is an equidigital number, since it uses as much as digits as its factorization.

1220209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71794.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 1220209 is about 1104.6307075217. The cubic root of 1220209 is about 106.8590743800.

The spelling of 1220209 in words is "one million, two hundred twenty thousand, two hundred nine".