66631633 has 2 divisors, whose sum is σ = 66631634. Its totient is φ = 66631632.

The previous prime is 66631603. The next prime is 66631637. The reversal of 66631633 is 33613666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61826769 + 4804864 = 7863^2 + 2192^2 .

It is a cyclic number.

It is not a de Polignac number, because 66631633 - 2¹³ = 66623441 is a prime.

It is not a weakly prime, because it can be changed into another prime (66631637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33315816 + 33315817.

It is an arithmetic number, because the mean of its divisors is an integer number (33315817).

Almost surely, 2^66631633 is an apocalyptic number.

It is an amenable number.

66631633 is a deficient number, since it is larger than the sum of its proper divisors (1).

66631633 is an equidigital number, since it uses as much as digits as its factorization.

66631633 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34992, while the sum is 34.

The square root of 66631633 is about 8162.8201621743. The cubic root of 66631633 is about 405.4090933138.

The spelling of 66631633 in words is "sixty-six million, six hundred thirty-one thousand, six hundred thirty-three".