1221424241221 has 4 divisors (see below), whose sum is σ = 1229621719500. Its totient is φ = 1213226762944.

The previous prime is 1221424241161. The next prime is 1221424241249.

1221424241221 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 51933396321 + 1169490844900 = 227889^2 + 1081430^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221424241221 - 2¹¹ = 1221424239173 is a prime.

It is a super-3 number, since 3×1221424241221³ (a number of 37 digits) contains 333 as substring.

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 1221424241221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221424241251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4098738916 + ... + 4098739213.

It is an arithmetic number, because the mean of its divisors is an integer number (307405429875).

Almost surely, 2^{1221424241221} is an apocalyptic number.

It is an amenable number.

1221424241221 is a deficient number, since it is larger than the sum of its proper divisors (8197478279).

1221424241221 is an equidigital number, since it uses as much as digits as its factorization.

1221424241221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8197478278.

The product of its digits is 4096, while the sum is 28.

The spelling of 1221424241221 in words is "one trillion, two hundred twenty-one billion, four hundred twenty-four million, two hundred forty-one thousand, two hundred twenty-one".