66524561 has 2 divisors, whose sum is σ = 66524562. Its totient is φ = 66524560.

The previous prime is 66524539. The next prime is 66524581. The reversal of 66524561 is 16542566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66520336 + 4225 = 8156^2 + 65^2 .

It is a cyclic number.

It is not a de Polignac number, because 66524561 - 2¹⁴ = 66508177 is a prime.

It is not a weakly prime, because it can be changed into another prime (66524531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33262280 + 33262281.

It is an arithmetic number, because the mean of its divisors is an integer number (33262281).

Almost surely, 2^66524561 is an apocalyptic number.

It is an amenable number.

66524561 is a deficient number, since it is larger than the sum of its proper divisors (1).

66524561 is an equidigital number, since it uses as much as digits as its factorization.

66524561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 43200, while the sum is 35.

The square root of 66524561 is about 8156.2590076579. The cubic root of 66524561 is about 405.1918229655.

The spelling of 66524561 in words is "sixty-six million, five hundred twenty-four thousand, five hundred sixty-one".