1211320213 has 4 divisors (see below), whose sum is σ = 1211457708. Its totient is φ = 1211182720.

The previous prime is 1211320207. The next prime is 1211320217. The reversal of 1211320213 is 3120231121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 742944049 + 468376164 = 27257^2 + 21642^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211320213 - 2²⁹ = 674449301 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211320217) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54556 + ... + 73477.

It is an arithmetic number, because the mean of its divisors is an integer number (302864427).

Almost surely, 2^1211320213 is an apocalyptic number.

It is an amenable number.

1211320213 is a deficient number, since it is larger than the sum of its proper divisors (137495).

1211320213 is an equidigital number, since it uses as much as digits as its factorization.

1211320213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137494.

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

The square root of 1211320213 is about 34804.0258159886. The cubic root of 1211320213 is about 1065.9896501500.

Adding to 1211320213 its reverse (3120231121), we get a palindrome (4331551334).

The spelling of 1211320213 in words is "one billion, two hundred eleven million, three hundred twenty thousand, two hundred thirteen".