666547506 has 12 divisors (see below), whose sum is σ = 1444186302. Its totient is φ = 222182496.

The previous prime is 666547501. The next prime is 666547579. The reversal of 666547506 is 605745666.

It can be written as a sum of positive squares in only one way, i.e., 363474225 + 303073281 = 19065^2 + 17409^2 .

It is not an unprimeable number, because it can be changed into a prime (666547501) 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 5 ways as a sum of consecutive naturals, for example, 18515191 + ... + 18515226.

Almost surely, 2^666547506 is an apocalyptic number.

666547506 is an abundant number, since it is smaller than the sum of its proper divisors (777638796).

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

666547506 is a wasteful number, since it uses less digits than its factorization.

666547506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37030425 (or 37030422 counting only the distinct ones).

The product of its (nonzero) digits is 907200, while the sum is 45.

The square root of 666547506 is about 25817.5813352064. The cubic root of 666547506 is about 873.5284134197.

The spelling of 666547506 in words is "six hundred sixty-six million, five hundred forty-seven thousand, five hundred six".