1311103111221 has 6 divisors (see below), whose sum is σ = 1893815605110. Its totient is φ = 874068740808.

The previous prime is 1311103111187. The next prime is 1311103111243. The reversal of 1311103111221 is 1221113011131.

1311103111221 is a `hidden beast` number, since 1 + 311 + 10 + 311 + 12 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1182232163025 + 128870948196 = 1087305^2 + 358986^2 .

It is not a de Polignac number, because 1311103111221 - 2¹⁰ = 1311103110197 is a prime.

It is a super-2 number, since 2×1311103111221² (a number of 25 digits) contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1311103111194 and 1311103111203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311103111261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 72839061726 + ... + 72839061743.

It is an arithmetic number, because the mean of its divisors is an integer number (315635934185).

Almost surely, 2^{1311103111221} is an apocalyptic number.

It is an amenable number.

1311103111221 is a deficient number, since it is larger than the sum of its proper divisors (582712493889).

1311103111221 is a wasteful number, since it uses less digits than its factorization.

1311103111221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145678123475 (or 145678123472 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 18.

Adding to 1311103111221 its reverse (1221113011131), we get a palindrome (2532216122352).

It can be divided in two parts, 131110 and 3111221, that added together give a triangular number (3242331 = T₂₅₄₆).

The spelling of 1311103111221 in words is "one trillion, three hundred eleven billion, one hundred three million, one hundred eleven thousand, two hundred twenty-one".