1221101121211 has 16 divisors (see below), whose sum is σ = 1250777438208. Its totient is φ = 1191775564000.

The previous prime is 1221101121203. The next prime is 1221101121271. The reversal of 1221101121211 is 1121211011221.

It is a cyclic number.

It is not a de Polignac number, because 1221101121211 - 2³ = 1221101121203 is a prime.

It is a super-2 number, since 2×1221101121211² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221101121271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 56087850 + ... + 56109616.

It is an arithmetic number, because the mean of its divisors is an integer number (78173589888).

Almost surely, 2^{1221101121211} is an apocalyptic number.

1221101121211 is a deficient number, since it is larger than the sum of its proper divisors (29676316997).

1221101121211 is a wasteful number, since it uses less digits than its factorization.

1221101121211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29762.

The product of its (nonzero) digits is 16, while the sum is 16.

Adding to 1221101121211 its reverse (1121211011221), we get a palindrome (2342312132432).

The spelling of 1221101121211 in words is "one trillion, two hundred twenty-one billion, one hundred one million, one hundred twenty-one thousand, two hundred eleven".