666783 has 24 divisors (see below), whose sum is σ = 1070160. Its totient is φ = 397440.

The previous prime is 666773. The next prime is 666811. The reversal of 666783 is 387666.

It is a happy number.

It is not a de Polignac number, because 666783 - 2⁵ = 666751 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666733) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4728 + ... + 4866.

It is an arithmetic number, because the mean of its divisors is an integer number (44590).

2⁶⁶⁶⁷⁸³ is an apocalyptic number.

666783 is a deficient number, since it is larger than the sum of its proper divisors (403377).

666783 is a wasteful number, since it uses less digits than its factorization.

666783 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199 (or 196 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 666783 is about 816.5678171469. The cubic root of 666783 is about 87.3631275045.

The spelling of 666783 in words is "six hundred sixty-six thousand, seven hundred eighty-three".