73043521 has 2 divisors, whose sum is σ = 73043522. Its totient is φ = 73043520.

The previous prime is 73043519. The next prime is 73043567. The reversal of 73043521 is 12534037.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71639296 + 1404225 = 8464^2 + 1185^2 .

It is an emirp because it is prime and its reverse (12534037) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 73043521 - 2¹ = 73043519 is a prime.

Together with 73043519, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (73043501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36521760 + 36521761.

It is an arithmetic number, because the mean of its divisors is an integer number (36521761).

Almost surely, 2^73043521 is an apocalyptic number.

It is an amenable number.

73043521 is a deficient number, since it is larger than the sum of its proper divisors (1).

73043521 is an equidigital number, since it uses as much as digits as its factorization.

73043521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2520, while the sum is 25.

The square root of 73043521 is about 8546.5502397166. The cubic root of 73043521 is about 418.0169574861.

Adding to 73043521 its reverse (12534037), we get a palindrome (85577558).

The spelling of 73043521 in words is "seventy-three million, forty-three thousand, five hundred twenty-one".