1666225220663 has 2 divisors, whose sum is σ = 1666225220664. Its totient is φ = 1666225220662.

The previous prime is 1666225220659. The next prime is 1666225220687. The reversal of 1666225220663 is 3660225226661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1666225220663 - 2² = 1666225220659 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1666225220603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833112610331 + 833112610332.

It is an arithmetic number, because the mean of its divisors is an integer number (833112610332).

Almost surely, 2^{1666225220663} is an apocalyptic number.

1666225220663 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666225220663 is an equidigital number, since it uses as much as digits as its factorization.

1666225220663 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1866240, while the sum is 47.

The spelling of 1666225220663 in words is "one trillion, six hundred sixty-six billion, two hundred twenty-five million, two hundred twenty thousand, six hundred sixty-three".