1211101221221 has 8 divisors (see below), whose sum is σ = 1213762604544. Its totient is φ = 1208440845360.

The previous prime is 1211101221139. The next prime is 1211101221223. The reversal of 1211101221221 is 1221221011121.

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-1211101221221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1211101221221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211101221223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2180795 + ... + 2679191.

It is an arithmetic number, because the mean of its divisors is an integer number (151720325568).

Almost surely, 2^{1211101221221} is an apocalyptic number.

It is an amenable number.

1211101221221 is a deficient number, since it is larger than the sum of its proper divisors (2661383323).

1211101221221 is an equidigital number, since it uses as much as digits as its factorization.

1211101221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 503731.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 1211101221221 its reverse (1221221011121), we get a palindrome (2432322232342).

The spelling of 1211101221221 in words is "one trillion, two hundred eleven billion, one hundred one million, two hundred twenty-one thousand, two hundred twenty-one".