1210218209 has 4 divisors (see below), whose sum is σ = 1262836416. Its totient is φ = 1157600004.

The previous prime is 1210218203. The next prime is 1210218221. The reversal of 1210218209 is 9028120121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9028120121 = 467 ⋅19332163.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1210218209 is a prime.

It is a super-2 number, since 2×1210218209² = 2929256226790335362, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1210218203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26309069 + ... + 26309114.

It is an arithmetic number, because the mean of its divisors is an integer number (315709104).

Almost surely, 2^1210218209 is an apocalyptic number.

It is an amenable number.

1210218209 is a deficient number, since it is larger than the sum of its proper divisors (52618207).

1210218209 is an equidigital number, since it uses as much as digits as its factorization.

1210218209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52618206.

The product of its (nonzero) digits is 576, while the sum is 26.

The square root of 1210218209 is about 34788.1906543011. The cubic root of 1210218209 is about 1065.6662891143. Note that the first 3 decimals are identical.

The spelling of 1210218209 in words is "one billion, two hundred ten million, two hundred eighteen thousand, two hundred nine".