1666505287505 has 16 divisors (see below), whose sum is σ = 2015074152000. Its totient is φ = 1323042104640.

The previous prime is 1666505287487. The next prime is 1666505287543. The reversal of 1666505287505 is 5057825056661.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-1666505287505 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 212375 + ... + 1837964.

It is an arithmetic number, because the mean of its divisors is an integer number (125942134500).

Almost surely, 2^{1666505287505} is an apocalyptic number.

It is an amenable number.

1666505287505 is a deficient number, since it is larger than the sum of its proper divisors (348568864495).

1666505287505 is a wasteful number, since it uses less digits than its factorization.

1666505287505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2051584.

The product of its (nonzero) digits is 15120000, while the sum is 56.

The spelling of 1666505287505 in words is "one trillion, six hundred sixty-six billion, five hundred five million, two hundred eighty-seven thousand, five hundred five".