66550243 has 2 divisors, whose sum is σ = 66550244. Its totient is φ = 66550242.

The previous prime is 66550241. The next prime is 66550303. The reversal of 66550243 is 34205566.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66550243 - 2¹ = 66550241 is a prime.

Together with 66550241, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (66550241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33275121 + 33275122.

It is an arithmetic number, because the mean of its divisors is an integer number (33275122).

Almost surely, 2^66550243 is an apocalyptic number.

66550243 is a deficient number, since it is larger than the sum of its proper divisors (1).

66550243 is an equidigital number, since it uses as much as digits as its factorization.

66550243 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21600, while the sum is 31.

The square root of 66550243 is about 8157.8332294795. The cubic root of 66550243 is about 405.2439580838.

The spelling of 66550243 in words is "sixty-six million, five hundred fifty thousand, two hundred forty-three".