1221111103231 has 4 divisors (see below), whose sum is σ = 1274202890352. Its totient is φ = 1168019316112.

The previous prime is 1221111103217. The next prime is 1221111103253. The reversal of 1221111103231 is 1323011111221.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1221111103231 - 2¹⁵ = 1221111070463 is a prime.

It is a super-2 number, since 2×1221111103231² (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 = 1221111103199 and 1221111103208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221111103271) 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, 26545893526 + ... + 26545893571.

It is an arithmetic number, because the mean of its divisors is an integer number (318550722588).

Almost surely, 2^{1221111103231} is an apocalyptic number.

1221111103231 is a deficient number, since it is larger than the sum of its proper divisors (53091787121).

1221111103231 is an equidigital number, since it uses as much as digits as its factorization.

1221111103231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53091787120.

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

Adding to 1221111103231 its reverse (1323011111221), we get a palindrome (2544122214452).

The spelling of 1221111103231 in words is "one trillion, two hundred twenty-one billion, one hundred eleven million, one hundred three thousand, two hundred thirty-one".