1243010043521 has 2 divisors, whose sum is σ = 1243010043522. Its totient is φ = 1243010043520.

The previous prime is 1243010043511. The next prime is 1243010043529. The reversal of 1243010043521 is 1253400103421.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1210561065025 + 32448978496 = 1100255^2 + 180136^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1243010043521 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1243010043529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621505021760 + 621505021761.

It is an arithmetic number, because the mean of its divisors is an integer number (621505021761).

Almost surely, 2^{1243010043521} is an apocalyptic number.

It is an amenable number.

1243010043521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243010043521 is an equidigital number, since it uses as much as digits as its factorization.

1243010043521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 26.

Adding to 1243010043521 its reverse (1253400103421), we get a palindrome (2496410146942).

The spelling of 1243010043521 in words is "one trillion, two hundred forty-three billion, ten million, forty-three thousand, five hundred twenty-one".