4043243521 has 2 divisors, whose sum is σ = 4043243522. Its totient is φ = 4043243520.

The previous prime is 4043243507. The next prime is 4043243549. The reversal of 4043243521 is 1253423404.

It is a happy number.

It is an a-pointer prime, because the next prime (4043243549) can be obtained adding 4043243521 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., 4030853121 + 12390400 = 63489^2 + 3520^2 .

It is a cyclic number.

It is not a de Polignac number, because 4043243521 - 2²³ = 4034854913 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 4043243521.

It is not a weakly prime, because it can be changed into another prime (4043243591) 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, 2021621760 + 2021621761.

It is an arithmetic number, because the mean of its divisors is an integer number (2021621761).

It is a Proth number, since it is equal to 61695 ⋅ 2¹⁶ + 1 and 61695 < 2¹⁶.

Almost surely, 2^4043243521 is an apocalyptic number.

It is an amenable number.

4043243521 is a deficient number, since it is larger than the sum of its proper divisors (1).

4043243521 is an equidigital number, since it uses as much as digits as its factorization.

4043243521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11520, while the sum is 28.

The square root of 4043243521 is about 63586.5042363551. The cubic root of 4043243521 is about 1593.1009615968.

Adding to 4043243521 its reverse (1253423404), we get a palindrome (5296666925).

The spelling of 4043243521 in words is "four billion, forty-three million, two hundred forty-three thousand, five hundred twenty-one".