1311202221 has 16 divisors (see below), whose sum is σ = 2038800000. Its totient is φ = 749257824.

The previous prime is 1311202199. The next prime is 1311202247. The reversal of 1311202221 is 1222021131.

It is not a de Polignac number, because 1311202221 - 2⁶ = 1311202157 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1311202221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311202021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 636096 + ... + 638153.

It is an arithmetic number, because the mean of its divisors is an integer number (127425000).

Almost surely, 2^1311202221 is an apocalyptic number.

It is an amenable number.

1311202221 is a deficient number, since it is larger than the sum of its proper divisors (727597779).

1311202221 is an equidigital number, since it uses as much as digits as its factorization.

1311202221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1274273 (or 1274259 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 1311202221 is about 36210.5263839122. The cubic root of 1311202221 is about 1094.5187994291.

Adding to 1311202221 its reverse (1222021131), we get a palindrome (2533223352).

The spelling of 1311202221 in words is "one billion, three hundred eleven million, two hundred two thousand, two hundred twenty-one".