1221101101111 has 4 divisors (see below), whose sum is σ = 1221237866800. Its totient is φ = 1220964335424.

The previous prime is 1221101101021. The next prime is 1221101101127. The reversal of 1221101101111 is 1111011011221.

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 1221101101111 - 2²¹ = 1221099003959 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221101101091 and 1221101101100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221101101141) 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, 68369451 + ... + 68387308.

It is an arithmetic number, because the mean of its divisors is an integer number (305309466700).

Almost surely, 2^{1221101101111} is an apocalyptic number.

1221101101111 is a deficient number, since it is larger than the sum of its proper divisors (136765689).

1221101101111 is an equidigital number, since it uses as much as digits as its factorization.

1221101101111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136765688.

The product of its (nonzero) digits is 4, while the sum is 13.

Adding to 1221101101111 its reverse (1111011011221), we get a palindrome (2332112112332).

It can be divided in two parts, 122110110 and 1111, that added together give a palindrome (122111221).

The spelling of 1221101101111 in words is "one trillion, two hundred twenty-one billion, one hundred one million, one hundred one thousand, one hundred eleven".