666586520 has 16 divisors (see below), whose sum is σ = 1499819760. Its totient is φ = 266634592.

The previous prime is 666586511. The next prime is 666586523. The reversal of 666586520 is 25685666.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666586523) 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 3 ways as a sum of consecutive naturals, for example, 8332292 + ... + 8332371.

It is an arithmetic number, because the mean of its divisors is an integer number (93738735).

Almost surely, 2^666586520 is an apocalyptic number.

It is an amenable number.

666586520 is an abundant number, since it is smaller than the sum of its proper divisors (833233240).

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

666586520 is a wasteful number, since it uses less digits than its factorization.

666586520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16664674 (or 16664670 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 44.

The square root of 666586520 is about 25818.3368945407. The cubic root of 666586520 is about 873.5454560522.

The spelling of 666586520 in words is "six hundred sixty-six million, five hundred eighty-six thousand, five hundred twenty".