1687018666889 has 2 divisors, whose sum is σ = 1687018666890. Its totient is φ = 1687018666888.

The previous prime is 1687018666867. The next prime is 1687018666903. The reversal of 1687018666889 is 9886668107861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1630453179664 + 56565487225 = 1276892^2 + 237835^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1687018666889 is a prime.

It is not a weakly prime, because it can be changed into another prime (1687018666189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 843509333444 + 843509333445.

It is an arithmetic number, because the mean of its divisors is an integer number (843509333445).

Almost surely, 2^{1687018666889} is an apocalyptic number.

It is an amenable number.

1687018666889 is a deficient number, since it is larger than the sum of its proper divisors (1).

1687018666889 is an equidigital number, since it uses as much as digits as its factorization.

1687018666889 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 334430208, while the sum is 74.

The spelling of 1687018666889 in words is "one trillion, six hundred eighty-seven billion, eighteen million, six hundred sixty-six thousand, eight hundred eighty-nine".