1311103231221 has 16 divisors (see below), whose sum is σ = 2066763715200. Its totient is φ = 723367299648.

The previous prime is 1311103231169. The next prime is 1311103231223. The reversal of 1311103231221 is 1221323011131.

It is not a de Polignac number, because 1311103231221 - 2⁶ = 1311103231157 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311103231223) 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, 1076438826 + ... + 1076440043.

It is an arithmetic number, because the mean of its divisors is an integer number (129172732200).

Almost surely, 2^{1311103231221} is an apocalyptic number.

It is an amenable number.

1311103231221 is a deficient number, since it is larger than the sum of its proper divisors (755660483979).

1311103231221 is a wasteful number, since it uses less digits than its factorization.

1311103231221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2152878908.

The product of its (nonzero) digits is 216, while the sum is 21.

Adding to 1311103231221 its reverse (1221323011131), we get a palindrome (2532426242352).

The spelling of 1311103231221 in words is "one trillion, three hundred eleven billion, one hundred three million, two hundred thirty-one thousand, two hundred twenty-one".