666561552 has 40 divisors (see below), whose sum is σ = 1743757440. Its totient is φ = 219373440.

The previous prime is 666561523. The next prime is 666561557. The reversal of 666561552 is 255165666.

666561552 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (666561557) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84099 + ... + 91682.

It is an arithmetic number, because the mean of its divisors is an integer number (43593936).

Almost surely, 2^666561552 is an apocalyptic number.

It is an amenable number.

666561552 is an abundant number, since it is smaller than the sum of its proper divisors (1077195888).

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

666561552 is a wasteful number, since it uses less digits than its factorization.

666561552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175871 (or 175865 counting only the distinct ones).

The product of its digits is 324000, while the sum is 42.

The square root of 666561552 is about 25817.8533577058. The cubic root of 666561552 is about 873.5345492633.

The spelling of 666561552 in words is "six hundred sixty-six million, five hundred sixty-one thousand, five hundred fifty-two".