1311203213 has 4 divisors (see below), whose sum is σ = 1313392800. Its totient is φ = 1309013628.

The previous prime is 1311203203. The next prime is 1311203219. The reversal of 1311203213 is 3123021131.

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: 3123021131 = 53 ⋅58924927.

It is a cyclic number.

It is not a de Polignac number, because 1311203213 - 2¹² = 1311199117 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1311203191 and 1311203200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311203219) 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, 1093895 + ... + 1095092.

It is an arithmetic number, because the mean of its divisors is an integer number (328348200).

Almost surely, 2^1311203213 is an apocalyptic number.

It is an amenable number.

1311203213 is a deficient number, since it is larger than the sum of its proper divisors (2189587).

1311203213 is an equidigital number, since it uses as much as digits as its factorization.

1311203213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2189586.

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 1311203213 is about 36210.5400815840. The cubic root of 1311203213 is about 1094.5190754512.

Adding to 1311203213 its reverse (3123021131), we get a palindrome (4434224344).

The spelling of 1311203213 in words is "one billion, three hundred eleven million, two hundred three thousand, two hundred thirteen".