1211100220221 has 8 divisors (see below), whose sum is σ = 1615326813984. Its totient is φ = 807136886640.

The previous prime is 1211100220193. The next prime is 1211100220223. The reversal of 1211100220221 is 1220220011121.

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

It is not a de Polignac number, because 1211100220221 - 2²⁶ = 1211033111357 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1211100220221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211100220223) 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, 65804310 + ... + 65822711.

It is an arithmetic number, because the mean of its divisors is an integer number (201915851748).

Almost surely, 2^{1211100220221} is an apocalyptic number.

It is an amenable number.

1211100220221 is a deficient number, since it is larger than the sum of its proper divisors (404226593763).

1211100220221 is a wasteful number, since it uses less digits than its factorization.

1211100220221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131630091.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 1211100220221 its reverse (1220220011121), we get a palindrome (2431320231342).

The spelling of 1211100220221 in words is "one trillion, two hundred eleven billion, one hundred million, two hundred twenty thousand, two hundred twenty-one".