1666461121399 has 2 divisors, whose sum is σ = 1666461121400. Its totient is φ = 1666461121398.

The previous prime is 1666461121373. The next prime is 1666461121499. The reversal of 1666461121399 is 9931211646661.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1666461121399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1666461121499) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833230560699 + 833230560700.

It is an arithmetic number, because the mean of its divisors is an integer number (833230560700).

Almost surely, 2^{1666461121399} is an apocalyptic number.

1666461121399 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666461121399 is an equidigital number, since it uses as much as digits as its factorization.

1666461121399 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2519424, while the sum is 55.

The spelling of 1666461121399 in words is "one trillion, six hundred sixty-six billion, four hundred sixty-one million, one hundred twenty-one thousand, three hundred ninety-nine".