1221100011221 has 8 divisors (see below), whose sum is σ = 1233227600544. Its totient is φ = 1208973157200.

The previous prime is 1221100011211. The next prime is 1221100011227.

1221100011221 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221100011221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221100011196 and 1221100011205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221100011227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3523310 + ... + 3854336.

It is an arithmetic number, because the mean of its divisors is an integer number (154153450068).

Almost surely, 2^{1221100011221} is an apocalyptic number.

It is an amenable number.

1221100011221 is a deficient number, since it is larger than the sum of its proper divisors (12127589323).

1221100011221 is a wasteful number, since it uses less digits than its factorization.

1221100011221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 367651.

The product of its (nonzero) digits is 16, while the sum is 14.

It can be divided in two parts, 12211000 and 11221, that added together give a palindrome (12222221).

The spelling of 1221100011221 in words is "one trillion, two hundred twenty-one billion, one hundred million, eleven thousand, two hundred twenty-one".