1221021101221 has 8 divisors (see below), whose sum is σ = 1222373901600. Its totient is φ = 1219668823632.

The previous prime is 1221021101219. The next prime is 1221021101231. The reversal of 1221021101221 is 1221011201221.

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

It is a cyclic number.

It is not a de Polignac number, because 1221021101221 - 2¹ = 1221021101219 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221021101195 and 1221021101204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221021101231) 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, 4639071 + ... + 4895203.

It is an arithmetic number, because the mean of its divisors is an integer number (152796737700).

Almost surely, 2^{1221021101221} is an apocalyptic number.

It is an amenable number.

1221021101221 is a deficient number, since it is larger than the sum of its proper divisors (1352800379).

1221021101221 is a wasteful number, since it uses less digits than its factorization.

1221021101221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261395.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 1221021101221 its reverse (1221011201221), we get a palindrome (2442032302442).

The spelling of 1221021101221 in words is "one trillion, two hundred twenty-one billion, twenty-one million, one hundred one thousand, two hundred twenty-one".