1311131201221 has 4 divisors (see below), whose sum is σ = 1311297532992. Its totient is φ = 1310964869452.

The previous prime is 1311131201201. The next prime is 1311131201279. The reversal of 1311131201221 is 1221021311131.

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.

It is a cyclic number.

It is not a de Polignac number, because 1311131201221 - 2⁵ = 1311131201189 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 (1311131201201) 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, 83154061 + ... + 83169826.

It is an arithmetic number, because the mean of its divisors is an integer number (327824383248).

Almost surely, 2^{1311131201221} is an apocalyptic number.

It is an amenable number.

1311131201221 is a deficient number, since it is larger than the sum of its proper divisors (166331771).

1311131201221 is an equidigital number, since it uses as much as digits as its factorization.

1311131201221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166331770.

The product of its (nonzero) digits is 72, while the sum is 19.

Adding to 1311131201221 its reverse (1221021311131), we get a palindrome (2532152512352).

The spelling of 1311131201221 in words is "one trillion, three hundred eleven billion, one hundred thirty-one million, two hundred one thousand, two hundred twenty-one".