1221220122221 has 8 divisors (see below), whose sum is σ = 1375215621888. Its totient is φ = 1074387204000.

The previous prime is 1221220122217. The next prime is 1221220122251. The reversal of 1221220122221 is 1222210221221.

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

It is not a de Polignac number, because 1221220122221 - 2² = 1221220122217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221220122193 and 1221220122202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221220122251) 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, 1790645000 + ... + 1790645681.

It is an arithmetic number, because the mean of its divisors is an integer number (171901952736).

Almost surely, 2^{1221220122221} is an apocalyptic number.

1221220122221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221220122221 is a deficient number, since it is larger than the sum of its proper divisors (153995499667).

1221220122221 is a wasteful number, since it uses less digits than its factorization.

1221220122221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3581290723.

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

Adding to 1221220122221 its reverse (1222210221221), we get a palindrome (2443430343442).

The spelling of 1221220122221 in words is "one trillion, two hundred twenty-one billion, two hundred twenty million, one hundred twenty-two thousand, two hundred twenty-one".