1221211121221 has 12 divisors (see below), whose sum is σ = 1511287475232. Its totient is φ = 966232974096.

The previous prime is 1221211121177. The next prime is 1221211121269.

It is a happy number.

1221211121221 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1221211121221 - 2¹³ = 1221211113029 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 (1221211125221) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 516148911 + ... + 516151276.

It is an arithmetic number, because the mean of its divisors is an integer number (125940622936).

Almost surely, 2^{1221211121221} is an apocalyptic number.

It is an amenable number.

1221211121221 is a deficient number, since it is larger than the sum of its proper divisors (290076354011).

1221211121221 is a wasteful number, since it uses less digits than its factorization.

1221211121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1032300220 (or 1032300207 counting only the distinct ones).

The product of its digits is 64, while the sum is 19.

The spelling of 1221211121221 in words is "one trillion, two hundred twenty-one billion, two hundred eleven million, one hundred twenty-one thousand, two hundred twenty-one".