1221202111221 has 64 divisors (see below), whose sum is σ = 1917281894400. Its totient is φ = 767067148800.

The previous prime is 1221202111211. The next prime is 1221202111223. The reversal of 1221202111221 is 1221112021221.

It is not a de Polignac number, because 1221202111221 - 2¹¹ = 1221202109173 is a prime.

It is a super-2 number, since 2×1221202111221² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221202111194 and 1221202111203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221202111223) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 7432485 + ... + 7595013.

It is an arithmetic number, because the mean of its divisors is an integer number (29957529600).

Almost surely, 2^{1221202111221} is an apocalyptic number.

It is an amenable number.

1221202111221 is a deficient number, since it is larger than the sum of its proper divisors (696079783179).

1221202111221 is a wasteful number, since it uses less digits than its factorization.

1221202111221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162807 (or 162801 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 1221202111221 its reverse (1221112021221), we get a palindrome (2442314132442).

The spelling of 1221202111221 in words is "one trillion, two hundred twenty-one billion, two hundred two million, one hundred eleven thousand, two hundred twenty-one".