665556606 has 48 divisors (see below), whose sum is σ = 1694150640. Its totient is φ = 186168960.

The previous prime is 665556601. The next prime is 665556637. The reversal of 665556606 is 606655566.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665556601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 126711 + ... + 131858.

It is an arithmetic number, because the mean of its divisors is an integer number (35294805).

Almost surely, 2^665556606 is an apocalyptic number.

665556606 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

665556606 is an abundant number, since it is smaller than the sum of its proper divisors (1028594034).

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

665556606 is a wasteful number, since it uses less digits than its factorization.

665556606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258601 (or 258598 counting only the distinct ones).

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

The square root of 665556606 is about 25798.3837865863. The cubic root of 665556606 is about 873.0953317165.

The spelling of 665556606 in words is "six hundred sixty-five million, five hundred fifty-six thousand, six hundred six".