1243726553 has 2 divisors, whose sum is σ = 1243726554. Its totient is φ = 1243726552.

The previous prime is 1243726507. The next prime is 1243726559. The reversal of 1243726553 is 3556273421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 712516249 + 531210304 = 26693^2 + 23048^2 .

It is a cyclic number.

It is not a de Polignac number, because 1243726553 - 2⁶ = 1243726489 is a prime.

It is not a weakly prime, because it can be changed into another prime (1243726559) 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, 621863276 + 621863277.

It is an arithmetic number, because the mean of its divisors is an integer number (621863277).

Almost surely, 2^1243726553 is an apocalyptic number.

It is an amenable number.

1243726553 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243726553 is an equidigital number, since it uses as much as digits as its factorization.

1243726553 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 151200, while the sum is 38.

The square root of 1243726553 is about 35266.5075248457. The cubic root of 1243726553 is about 1075.4122242393.

Adding to 1243726553 its reverse (3556273421), we get a palindrome (4799999974).

The spelling of 1243726553 in words is "one billion, two hundred forty-three million, seven hundred twenty-six thousand, five hundred fifty-three".