1666412787563 has 2 divisors, whose sum is σ = 1666412787564. Its totient is φ = 1666412787562.

The previous prime is 1666412787503. The next prime is 1666412787587. The reversal of 1666412787563 is 3657872146661.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1666412787563 - 2⁸ = 1666412787307 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1666412787496 and 1666412787505.

It is not a weakly prime, because it can be changed into another prime (1666412787503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833206393781 + 833206393782.

It is an arithmetic number, because the mean of its divisors is an integer number (833206393782).

Almost surely, 2^{1666412787563} is an apocalyptic number.

1666412787563 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666412787563 is an equidigital number, since it uses as much as digits as its factorization.

1666412787563 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60963840, while the sum is 62.

The spelling of 1666412787563 in words is "one trillion, six hundred sixty-six billion, four hundred twelve million, seven hundred eighty-seven thousand, five hundred sixty-three".