1221120311013 has 24 divisors (see below), whose sum is σ = 1811572347000. Its totient is φ = 792051571584.

The previous prime is 1221120310987. The next prime is 1221120311029. The reversal of 1221120311013 is 3101130211221.

1221120311013 is a `hidden beast` number, since 1 + 221 + 120 + 311 + 0 + 13 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 133650929889 + 1087469381124 = 365583^2 + 1042818^2 .

It is not a de Polignac number, because 1221120311013 - 2⁸ = 1221120310757 is a prime.

It is a super-2 number, since 2×1221120311013² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221120311063) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17263723 + ... + 17334311.

It is an arithmetic number, because the mean of its divisors is an integer number (75482181125).

Almost surely, 2^{1221120311013} is an apocalyptic number.

It is an amenable number.

1221120311013 is a deficient number, since it is larger than the sum of its proper divisors (590452035987).

1221120311013 is a wasteful number, since it uses less digits than its factorization.

1221120311013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122581 (or 122578 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

Adding to 1221120311013 its reverse (3101130211221), we get a palindrome (4322250522234).

The spelling of 1221120311013 in words is "one trillion, two hundred twenty-one billion, one hundred twenty million, three hundred eleven thousand, thirteen".