1221221202221 has 8 divisors (see below), whose sum is σ = 1252141317504. Its totient is φ = 1190355098080.

The previous prime is 1221221202163. The next prime is 1221221202259. The reversal of 1221221202221 is 1222021221221.

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 1221221202221 - 2³⁰ = 1220147460397 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221221202193 and 1221221202202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221221202121) 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, 13456991 + ... + 13547436.

It is an arithmetic number, because the mean of its divisors is an integer number (156517664688).

Almost surely, 2^{1221221202221} is an apocalyptic number.

It is an amenable number.

1221221202221 is a deficient number, since it is larger than the sum of its proper divisors (30920115283).

1221221202221 is a wasteful number, since it uses less digits than its factorization.

1221221202221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27005571.

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 1221221202221 its reverse (1222021221221), we get a palindrome (2443242423442).

The spelling of 1221221202221 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-one million, two hundred two thousand, two hundred twenty-one".