668529556 has 24 divisors (see below), whose sum is σ = 1241885736. Its totient is φ = 313804800.

The previous prime is 668529553. The next prime is 668529581. The reversal of 668529556 is 655925866.

It can be written as a sum of positive squares in 4 ways, for example, as 298736656 + 369792900 = 17284^2 + 19230^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668529553) 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 7 ways as a sum of consecutive naturals, for example, 15010 + ... + 39526.

It is an arithmetic number, because the mean of its divisors is an integer number (51745239).

Almost surely, 2^668529556 is an apocalyptic number.

It is an amenable number.

668529556 is a deficient number, since it is larger than the sum of its proper divisors (573356180).

668529556 is a wasteful number, since it uses less digits than its factorization.

668529556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24939 (or 24937 counting only the distinct ones).

The product of its digits is 3888000, while the sum is 52.

The square root of 668529556 is about 25855.9385054962. The cubic root of 668529556 is about 874.3933998665.

The spelling of 668529556 in words is "six hundred sixty-eight million, five hundred twenty-nine thousand, five hundred fifty-six".