1666306782 has 128 divisors (see below), whose sum is σ = 4499712000. Its totient is φ = 446197248.

The previous prime is 1666306753. The next prime is 1666306793. The reversal of 1666306782 is 2876036661.

It is a congruent number.

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 63 ways as a sum of consecutive naturals, for example, 2242303 + ... + 2243045.

It is an arithmetic number, because the mean of its divisors is an integer number (35154000).

Almost surely, 2^1666306782 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1666306782, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2249856000).

1666306782 is an abundant number, since it is smaller than the sum of its proper divisors (2833405218).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1666306782 is a wasteful number, since it uses less digits than its factorization.

1666306782 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1127 (or 1121 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 45.

The square root of 1666306782 is about 40820.4211394248. The cubic root of 1666306782 is about 1185.5457572628.

The spelling of 1666306782 in words is "one billion, six hundred sixty-six million, three hundred six thousand, seven hundred eighty-two".