1211503343213 has 2 divisors, whose sum is σ = 1211503343214. Its totient is φ = 1211503343212.

The previous prime is 1211503343209. The next prime is 1211503343249. The reversal of 1211503343213 is 3123433051121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 605841176164 + 605662167049 = 778358^2 + 778243^2 .

It is an emirp because it is prime and its reverse (3123433051121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1211503343213 - 2² = 1211503343209 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211503343263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605751671606 + 605751671607.

It is an arithmetic number, because the mean of its divisors is an integer number (605751671607).

Almost surely, 2^{1211503343213} is an apocalyptic number.

It is an amenable number.

1211503343213 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211503343213 is an equidigital number, since it uses as much as digits as its factorization.

1211503343213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 29.

Adding to 1211503343213 its reverse (3123433051121), we get a palindrome (4334936394334).

The spelling of 1211503343213 in words is "one trillion, two hundred eleven billion, five hundred three million, three hundred forty-three thousand, two hundred thirteen".