1666843509195 has 64 divisors (see below), whose sum is σ = 3023093404800. Its totient is φ = 871215206400.

The previous prime is 1666843509187. The next prime is 1666843509197. The reversal of 1666843509195 is 5919053486661.

It is not a de Polignac number, because 1666843509195 - 2³ = 1666843509187 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1666843509197) 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 in 63 ways as a sum of consecutive naturals, for example, 743845 + ... + 1971545.

It is an arithmetic number, because the mean of its divisors is an integer number (47235834450).

Almost surely, 2^{1666843509195} is an apocalyptic number.

1666843509195 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1666843509195 is a deficient number, since it is larger than the sum of its proper divisors (1356249895605).

1666843509195 is a wasteful number, since it uses less digits than its factorization.

1666843509195 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1227917 (or 1227911 counting only the distinct ones).

The product of its (nonzero) digits is 41990400, while the sum is 63.

The spelling of 1666843509195 in words is "one trillion, six hundred sixty-six billion, eight hundred forty-three million, five hundred nine thousand, one hundred ninety-five".