1221200000221 has 8 divisors (see below), whose sum is σ = 1223433255384. Its totient is φ = 1218968013120.

The previous prime is 1221200000203. The next prime is 1221200000249. The reversal of 1221200000221 is 1220000021221.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 617773992196 + 603426008025 = 785986^2 + 776805^2 .

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 1221200000221 - 2⁷ = 1221200000093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221200000521) 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, 1621651 + ... + 2252143.

It is an arithmetic number, because the mean of its divisors is an integer number (152929156923).

Almost surely, 2^{1221200000221} is an apocalyptic number.

It is an amenable number.

1221200000221 is a deficient number, since it is larger than the sum of its proper divisors (2233255163).

1221200000221 is an equidigital number, since it uses as much as digits as its factorization.

1221200000221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 634031.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 1221200000221 its reverse (1220000021221), we get a palindrome (2441200021442).

The spelling of 1221200000221 in words is "one trillion, two hundred twenty-one billion, two hundred million, two hundred twenty-one", and thus it is an aban number.