1311242221 has 8 divisors (see below), whose sum is σ = 1369630080. Its totient is φ = 1253732592.

The previous prime is 1311242203. The next prime is 1311242227. The reversal of 1311242221 is 1222421131.

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

It is a cyclic number.

It is not a de Polignac number, because 1311242221 - 2²³ = 1302853613 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 (1311242227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 216505 + ... + 222478.

It is an arithmetic number, because the mean of its divisors is an integer number (171203760).

Almost surely, 2^1311242221 is an apocalyptic number.

It is an amenable number.

1311242221 is a deficient number, since it is larger than the sum of its proper divisors (58387859).

1311242221 is a wasteful number, since it uses less digits than its factorization.

1311242221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 439115.

The product of its digits is 192, while the sum is 19.

The square root of 1311242221 is about 36211.0787052802. The cubic root of 1311242221 is about 1094.5299292422.

Adding to 1311242221 its reverse (1222421131), we get a palindrome (2533663352).

The spelling of 1311242221 in words is "one billion, three hundred eleven million, two hundred forty-two thousand, two hundred twenty-one".