1221121101221 has 8 divisors (see below), whose sum is σ = 1477659147840. Its totient is φ = 985106098368.

The previous prime is 1221121101089. The next prime is 1221121101241. The reversal of 1221121101221 is 1221011211221.

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

It is not a de Polignac number, because 1221121101221 - 2³⁰ = 1220047359397 is a prime.

It is a super-2 number, since 2×1221121101221² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17).

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 1221121101221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221121101241) 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, 5130760811 + ... + 5130761048.

It is an arithmetic number, because the mean of its divisors is an integer number (184707393480).

Almost surely, 2^{1221121101221} is an apocalyptic number.

It is an amenable number.

1221121101221 is a deficient number, since it is larger than the sum of its proper divisors (256538046619).

1221121101221 is a wasteful number, since it uses less digits than its factorization.

1221121101221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10261521883.

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

Adding to 1221121101221 its reverse (1221011211221), we get a palindrome (2442132312442).

The spelling of 1221121101221 in words is "one trillion, two hundred twenty-one billion, one hundred twenty-one million, one hundred one thousand, two hundred twenty-one".