1666412787503 has 2 divisors, whose sum is σ = 1666412787504. Its totient is φ = 1666412787502.

The previous prime is 1666412787491. The next prime is 1666412787563. The reversal of 1666412787503 is 3057872146661.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1666412787503 - 2¹⁸ = 1666412525359 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1666412787563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833206393751 + 833206393752.

It is an arithmetic number, because the mean of its divisors is an integer number (833206393752).

Almost surely, 2^{1666412787503} is an apocalyptic number.

1666412787503 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666412787503 is an equidigital number, since it uses as much as digits as its factorization.

1666412787503 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10160640, while the sum is 56.

The spelling of 1666412787503 in words is "one trillion, six hundred sixty-six billion, four hundred twelve million, seven hundred eighty-seven thousand, five hundred three".