666782505 has 24 divisors (see below), whose sum is σ = 1158288768. Its totient is φ = 354838176.

The previous prime is 666782401. The next prime is 666782527. The reversal of 666782505 is 505287666.

It is not a de Polignac number, because 666782505 - 2⁹ = 666781993 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

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 23 ways as a sum of consecutive naturals, for example, 4834 + ... + 36836.

It is an arithmetic number, because the mean of its divisors is an integer number (48262032).

Almost surely, 2^666782505 is an apocalyptic number.

It is an amenable number.

666782505 is a deficient number, since it is larger than the sum of its proper divisors (491506263).

666782505 is a wasteful number, since it uses less digits than its factorization.

666782505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32477 (or 32474 counting only the distinct ones).

The product of its (nonzero) digits is 604800, while the sum is 45.

The square root of 666782505 is about 25822.1320769606. The cubic root of 666782505 is about 873.6310588586.

The spelling of 666782505 in words is "six hundred sixty-six million, seven hundred eighty-two thousand, five hundred five".