43661573 has 2 divisors, whose sum is σ = 43661574. Its totient is φ = 43661572.

The previous prime is 43661561. The next prime is 43661581. The reversal of 43661573 is 37516634.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29084449 + 14577124 = 5393^2 + 3818^2 .

It is a cyclic number.

It is not a de Polignac number, because 43661573 - 2⁴ = 43661557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43661533) 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, 21830786 + 21830787.

It is an arithmetic number, because the mean of its divisors is an integer number (21830787).

Almost surely, 2^43661573 is an apocalyptic number.

It is an amenable number.

43661573 is a deficient number, since it is larger than the sum of its proper divisors (1).

43661573 is an equidigital number, since it uses as much as digits as its factorization.

43661573 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 45360, while the sum is 35.

The square root of 43661573 is about 6607.6904437178. The cubic root of 43661573 is about 352.1273778200.

The spelling of 43661573 in words is "forty-three million, six hundred sixty-one thousand, five hundred seventy-three".