666556056 has 24 divisors (see below), whose sum is σ = 1805256180. Its totient is φ = 222185328.

The previous prime is 666556049. The next prime is 666556057. The reversal of 666556056 is 650655666.

It is a tau number, because it is divible by the number of its divisors (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666556057) 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, 4628790 + ... + 4628933.

Almost surely, 2^666556056 is an apocalyptic number.

It is an amenable number.

666556056 is an abundant number, since it is smaller than the sum of its proper divisors (1138700124).

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

666556056 is a wasteful number, since it uses less digits than its factorization.

666556056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9257735 (or 9257728 counting only the distinct ones).

The product of its (nonzero) digits is 972000, while the sum is 45.

The square root of 666556056 is about 25817.7469195126. The cubic root of 666556056 is about 873.5321484053.

The spelling of 666556056 in words is "six hundred sixty-six million, five hundred fifty-six thousand, fifty-six".