1221102202221 has 24 divisors (see below), whose sum is σ = 2025432683040. Its totient is φ = 701111311200.

The previous prime is 1221102202213. The next prime is 1221102202241. The reversal of 1221102202221 is 1222022011221.

It is a happy number.

1221102202221 is a `hidden beast` number, since 1 + 221 + 1 + 0 + 220 + 2 + 221 = 666.

It is not a de Polignac number, because 1221102202221 - 2³ = 1221102202213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221102202194 and 1221102202203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221102202211) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 324586690 + ... + 324590451.

It is an arithmetic number, because the mean of its divisors is an integer number (84393028460).

Almost surely, 2^{1221102202221} is an apocalyptic number.

1221102202221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221102202221 is a deficient number, since it is larger than the sum of its proper divisors (804330480819).

1221102202221 is a wasteful number, since it uses less digits than its factorization.

1221102202221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 649177177 (or 649177174 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 1221102202221 its reverse (1222022011221), we get a palindrome (2443124213442).

The spelling of 1221102202221 in words is "one trillion, two hundred twenty-one billion, one hundred two million, two hundred two thousand, two hundred twenty-one".