66631603 has 2 divisors, whose sum is σ = 66631604. Its totient is φ = 66631602.

The previous prime is 66631577. The next prime is 66631633. The reversal of 66631603 is 30613666.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66631603 - 2⁹ = 66631091 is a prime.

It is not a weakly prime, because it can be changed into another prime (66631633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33315801 + 33315802.

It is an arithmetic number, because the mean of its divisors is an integer number (33315802).

Almost surely, 2^66631603 is an apocalyptic number.

66631603 is a deficient number, since it is larger than the sum of its proper divisors (1).

66631603 is an equidigital number, since it uses as much as digits as its factorization.

66631603 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 31.

The square root of 66631603 is about 8162.8183245739. The cubic root of 66631603 is about 405.4090324704.

The spelling of 66631603 in words is "sixty-six million, six hundred thirty-one thousand, six hundred three".