1221153311131 has 16 divisors (see below), whose sum is σ = 1327507096608. Its totient is φ = 1116604569600.

The previous prime is 1221153311117. The next prime is 1221153311149. The reversal of 1221153311131 is 1311133511221.

It is not a de Polignac number, because 1221153311131 - 2⁷ = 1221153311003 is a prime.

It is a super-2 number, since 2×1221153311131² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221153311096 and 1221153311105.

It is not an unprimeable number, because it can be changed into a prime (1221153311431) 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 15 ways as a sum of consecutive naturals, for example, 304891 + ... + 1592251.

It is an arithmetic number, because the mean of its divisors is an integer number (82969193538).

Almost surely, 2^{1221153311131} is an apocalyptic number.

1221153311131 is a deficient number, since it is larger than the sum of its proper divisors (106353785477).

1221153311131 is a wasteful number, since it uses less digits than its factorization.

1221153311131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1288062.

The product of its digits is 540, while the sum is 25.

Adding to 1221153311131 its reverse (1311133511221), we get a palindrome (2532286822352).

The spelling of 1221153311131 in words is "one trillion, two hundred twenty-one billion, one hundred fifty-three million, three hundred eleven thousand, one hundred thirty-one".