1221211002221 has 8 divisors (see below), whose sum is σ = 1406323685184. Its totient is φ = 1038761811360.

The previous prime is 1221211002103. The next prime is 1221211002223. The reversal of 1221211002221 is 1222001121221.

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

It is not a de Polignac number, because 1221211002221 - 2³⁴ = 1204031133037 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221211002221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221211002223) 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, 665872040 + ... + 665873873.

It is an arithmetic number, because the mean of its divisors is an integer number (175790460648).

Almost surely, 2^{1221211002221} is an apocalyptic number.

It is an amenable number.

1221211002221 is a deficient number, since it is larger than the sum of its proper divisors (185112682963).

1221211002221 is a wasteful number, since it uses less digits than its factorization.

1221211002221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1331746051.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 1221211002221 its reverse (1222001121221), we get a palindrome (2443212123442).

The spelling of 1221211002221 in words is "one trillion, two hundred twenty-one billion, two hundred eleven million, two thousand, two hundred twenty-one".