66128663 has 2 divisors, whose sum is σ = 66128664. Its totient is φ = 66128662.

The previous prime is 66128659. The next prime is 66128677. The reversal of 66128663 is 36682166.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66128663 - 2² = 66128659 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66128603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33064331 + 33064332.

It is an arithmetic number, because the mean of its divisors is an integer number (33064332).

Almost surely, 2^66128663 is an apocalyptic number.

66128663 is a deficient number, since it is larger than the sum of its proper divisors (1).

66128663 is an equidigital number, since it uses as much as digits as its factorization.

66128663 is an evil number, because the sum of its binary digits is even.

The product of its digits is 62208, while the sum is 38.

The square root of 66128663 is about 8131.9532094079. The cubic root of 66128663 is about 404.3864366858.

The spelling of 66128663 in words is "sixty-six million, one hundred twenty-eight thousand, six hundred sixty-three".