1311321221 has 8 divisors (see below), whose sum is σ = 1498872000. Its totient is φ = 1123825248.

The previous prime is 1311321211. The next prime is 1311321229. The reversal of 1311321221 is 1221231131.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1311321221 - 2¹⁴ = 1311304837 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1311321221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311321229) 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 7 ways as a sum of consecutive naturals, for example, 84905 + ... + 99153.

It is an arithmetic number, because the mean of its divisors is an integer number (187359000).

Almost surely, 2^1311321221 is an apocalyptic number.

It is an amenable number.

1311321221 is a deficient number, since it is larger than the sum of its proper divisors (187550779).

1311321221 is a wasteful number, since it uses less digits than its factorization.

1311321221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27403.

The product of its digits is 72, while the sum is 17.

The square root of 1311321221 is about 36212.1695152334. The cubic root of 1311321221 is about 1094.5519099580.

Adding to 1311321221 its reverse (1221231131), we get a palindrome (2532552352).

The spelling of 1311321221 in words is "one billion, three hundred eleven million, three hundred twenty-one thousand, two hundred twenty-one".