1221200011221 has 8 divisors (see below), whose sum is σ = 1650571704960. Its totient is φ = 802980829152.

The previous prime is 1221200011217. The next prime is 1221200011237. The reversal of 1221200011221 is 1221100021221.

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

It is not a de Polignac number, because 1221200011221 - 2² = 1221200011217 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1221200011221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221200011721) 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, 2788127661 + ... + 2788128098.

It is an arithmetic number, because the mean of its divisors is an integer number (206321463120).

Almost surely, 2^{1221200011221} is an apocalyptic number.

It is an amenable number.

1221200011221 is a deficient number, since it is larger than the sum of its proper divisors (429371693739).

1221200011221 is an equidigital number, since it uses as much as digits as its factorization.

1221200011221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5576255835.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 1221200011221 its reverse (1221100021221), we get a palindrome (2442300032442).

The spelling of 1221200011221 in words is "one trillion, two hundred twenty-one billion, two hundred million, eleven thousand, two hundred twenty-one".