1212843209 has 2 divisors, whose sum is σ = 1212843210. Its totient is φ = 1212843208.

The previous prime is 1212843197. The next prime is 1212843241. The reversal of 1212843209 is 9023482121.

It is an a-pointer prime, because the next prime (1212843241) can be obtained adding 1212843209 to its sum of digits (32).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 781034809 + 431808400 = 27947^2 + 20780^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212843209 - 2⁴ = 1212843193 is a prime.

It is not a weakly prime, because it can be changed into another prime (1212843409) 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, 606421604 + 606421605.

It is an arithmetic number, because the mean of its divisors is an integer number (606421605).

Almost surely, 2^1212843209 is an apocalyptic number.

It is an amenable number.

1212843209 is a deficient number, since it is larger than the sum of its proper divisors (1).

1212843209 is an equidigital number, since it uses as much as digits as its factorization.

1212843209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 1212843209 is about 34825.8985383005. The cubic root of 1212843209 is about 1066.4362202149.

The spelling of 1212843209 in words is "one billion, two hundred twelve million, eight hundred forty-three thousand, two hundred nine".