1221350531221 has 4 divisors (see below), whose sum is σ = 1221352911072. Its totient is φ = 1221348151372.

The previous prime is 1221350531117. The next prime is 1221350531239.

1221350531221 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221350531221 is a prime.

It is a super-2 number, since 2×1221350531221² (a number of 25 digits) contains 22 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 1221350531221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221350531321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66691 + ... + 1564336.

It is an arithmetic number, because the mean of its divisors is an integer number (305338227768).

Almost surely, 2^{1221350531221} is an apocalyptic number.

It is an amenable number.

1221350531221 is a deficient number, since it is larger than the sum of its proper divisors (2379851).

1221350531221 is an equidigital number, since it uses as much as digits as its factorization.

1221350531221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2379850.

The product of its (nonzero) digits is 3600, while the sum is 28.

It can be divided in two parts, 1221350 and 531221, that added together give a palindrome (1752571).

The spelling of 1221350531221 in words is "one trillion, two hundred twenty-one billion, three hundred fifty million, five hundred thirty-one thousand, two hundred twenty-one".