1221101110221 has 8 divisors (see below), whose sum is σ = 1636399458144. Its totient is φ = 809935084560.

The previous prime is 1221101110199. The next prime is 1221101110223. The reversal of 1221101110221 is 1220111011221.

It is a happy number.

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

It is not a de Polignac number, because 1221101110221 - 2¹⁵ = 1221101077453 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1221101110221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221101110223) 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, 1033079875 + ... + 1033081056.

It is an arithmetic number, because the mean of its divisors is an integer number (204549932268).

Almost surely, 2^{1221101110221} is an apocalyptic number.

It is an amenable number.

1221101110221 is a deficient number, since it is larger than the sum of its proper divisors (415298347923).

1221101110221 is a wasteful number, since it uses less digits than its factorization.

1221101110221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2066161131.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 1221101110221 its reverse (1220111011221), we get a palindrome (2441212121442).

The spelling of 1221101110221 in words is "one trillion, two hundred twenty-one billion, one hundred one million, one hundred ten thousand, two hundred twenty-one".