1211243213 has 2 divisors, whose sum is σ = 1211243214. Its totient is φ = 1211243212.

The previous prime is 1211243123. The next prime is 1211243233. The reversal of 1211243213 is 3123421121.

Together with previous prime (1211243123) it forms an Ormiston pair, because they use the same digits, order apart.

It is an a-pointer prime, because the next prime (1211243233) can be obtained adding 1211243213 to its sum of digits (20).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1211179204 + 64009 = 34802^2 + 253^2 .

It is an emirp because it is prime and its reverse (3123421121) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1211243213 is a prime.

It is a super-2 number, since 2×1211243213² = 2934220242077126738, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211243233) 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 as a sum of consecutive naturals, namely, 605621606 + 605621607.

It is an arithmetic number, because the mean of its divisors is an integer number (605621607).

Almost surely, 2^1211243213 is an apocalyptic number.

It is an amenable number.

1211243213 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211243213 is an equidigital number, since it uses as much as digits as its factorization.

1211243213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 288, while the sum is 20.

The square root of 1211243213 is about 34802.9196045389. The cubic root of 1211243213 is about 1065.9670624143.

Adding to 1211243213 its reverse (3123421121), we get a palindrome (4334664334).

The spelling of 1211243213 in words is "one billion, two hundred eleven million, two hundred forty-three thousand, two hundred thirteen".