1244221621 has 2 divisors, whose sum is σ = 1244221622. Its totient is φ = 1244221620.

The previous prime is 1244221613. The next prime is 1244221651. The reversal of 1244221621 is 1261224421.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 902341521 + 341880100 = 30039^2 + 18490^2 .

It is an emirp because it is prime and its reverse (1261224421) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1244221621 - 2³ = 1244221613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1244221651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 622110810 + 622110811.

It is an arithmetic number, because the mean of its divisors is an integer number (622110811).

Almost surely, 2^1244221621 is an apocalyptic number.

It is an amenable number.

1244221621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1244221621 is an equidigital number, since it uses as much as digits as its factorization.

1244221621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1536, while the sum is 25.

The square root of 1244221621 is about 35273.5257806758. The cubic root of 1244221621 is about 1075.5548953519.

The spelling of 1244221621 in words is "one billion, two hundred forty-four million, two hundred twenty-one thousand, six hundred twenty-one".