1243222021 has 2 divisors, whose sum is σ = 1243222022. Its totient is φ = 1243222020.

The previous prime is 1243222009. The next prime is 1243222031. The reversal of 1243222021 is 1202223421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1135353025 + 107868996 = 33695^2 + 10386^2 .

It is a cyclic number.

It is not a de Polignac number, because 1243222021 - 2⁷ = 1243221893 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1243222021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1243222031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621611010 + 621611011.

It is an arithmetic number, because the mean of its divisors is an integer number (621611011).

Almost surely, 2^1243222021 is an apocalyptic number.

It is an amenable number.

1243222021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243222021 is an equidigital number, since it uses as much as digits as its factorization.

1243222021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 1243222021 is about 35259.3536667932. The cubic root of 1243222021 is about 1075.2667867867.

Adding to 1243222021 its reverse (1202223421), we get a palindrome (2445445442).

It can be divided in two parts, 12432 and 22021, that added together give a triangular number (34453 = T₂₆₂).

The spelling of 1243222021 in words is "one billion, two hundred forty-three million, two hundred twenty-two thousand, twenty-one".