666502646 has 16 divisors (see below), whose sum is σ = 1063005120. Its totient is φ = 312332160.

The previous prime is 666502633. The next prime is 666502649. The reversal of 666502646 is 646205666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666502649) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 32885 + ... + 49136.

It is an arithmetic number, because the mean of its divisors is an integer number (66437820).

Almost surely, 2^666502646 is an apocalyptic number.

666502646 is a deficient number, since it is larger than the sum of its proper divisors (396502474).

666502646 is a wasteful number, since it uses less digits than its factorization.

666502646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82279.

The product of its (nonzero) digits is 311040, while the sum is 41.

The square root of 666502646 is about 25816.7125327761. The cubic root of 666502646 is about 873.5088162350.

It can be divided in two parts, 66650 and 2646, that added together give a palindrome (69296).

The spelling of 666502646 in words is "six hundred sixty-six million, five hundred two thousand, six hundred forty-six".