1213220311 has 4 divisors (see below), whose sum is σ = 1216421800. Its totient is φ = 1210018824.

The previous prime is 1213220303. The next prime is 1213220339. The reversal of 1213220311 is 1130223121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1130223121 = 17 ⋅66483713.

It is a cyclic number.

It is not a de Polignac number, because 1213220311 - 2³ = 1213220303 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 (1213221311) 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 in 3 ways as a sum of consecutive naturals, for example, 1600176 + ... + 1600933.

It is an arithmetic number, because the mean of its divisors is an integer number (304105450).

Almost surely, 2^1213220311 is an apocalyptic number.

1213220311 is a deficient number, since it is larger than the sum of its proper divisors (3201489).

1213220311 is an equidigital number, since it uses as much as digits as its factorization.

1213220311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3201488.

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

The square root of 1213220311 is about 34831.3122204720. The cubic root of 1213220311 is about 1066.5467356154.

Adding to 1213220311 its reverse (1130223121), we get a palindrome (2343443432).

The spelling of 1213220311 in words is "one billion, two hundred thirteen million, two hundred twenty thousand, three hundred eleven".