66501563 has 2 divisors, whose sum is σ = 66501564. Its totient is φ = 66501562.

The previous prime is 66501559. The next prime is 66501583. The reversal of 66501563 is 36510566.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66501563 - 2² = 66501559 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (66501583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33250781 + 33250782.

It is an arithmetic number, because the mean of its divisors is an integer number (33250782).

Almost surely, 2^66501563 is an apocalyptic number.

66501563 is a deficient number, since it is larger than the sum of its proper divisors (1).

66501563 is an equidigital number, since it uses as much as digits as its factorization.

66501563 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16200, while the sum is 32.

The square root of 66501563 is about 8154.8490482657. The cubic root of 66501563 is about 405.1451250470.

The spelling of 66501563 in words is "sixty-six million, five hundred one thousand, five hundred sixty-three".