1213444312021 has 2 divisors, whose sum is σ = 1213444312022. Its totient is φ = 1213444312020.

The previous prime is 1213444312013. The next prime is 1213444312049. The reversal of 1213444312021 is 1202134443121.

It is a happy number.

It is an a-pointer prime, because the next prime (1213444312049) can be obtained adding 1213444312021 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1208924439121 + 4519872900 = 1099511^2 + 67230^2 .

It is a cyclic number.

It is not a de Polignac number, because 1213444312021 - 2³ = 1213444312013 is a prime.

It is a super-2 number, since 2×1213444312021² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1213444312081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606722156010 + 606722156011.

It is an arithmetic number, because the mean of its divisors is an integer number (606722156011).

Almost surely, 2^{1213444312021} is an apocalyptic number.

It is an amenable number.

1213444312021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1213444312021 is an equidigital number, since it uses as much as digits as its factorization.

1213444312021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4608, while the sum is 28.

Adding to 1213444312021 its reverse (1202134443121), we get a palindrome (2415578755142).

The spelling of 1213444312021 in words is "one trillion, two hundred thirteen billion, four hundred forty-four million, three hundred twelve thousand, twenty-one".