66681500 has 48 divisors (see below), whose sum is σ = 146598816. Its totient is φ = 26496000.

The previous prime is 66681499. The next prime is 66681521. The reversal of 66681500 is 518666.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 96155 + ... + 96845.

It is an arithmetic number, because the mean of its divisors is an integer number (3054142).

Almost surely, 2^66681500 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66681500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (73299408).

66681500 is an abundant number, since it is smaller than the sum of its proper divisors (79917316).

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

66681500 is a wasteful number, since it uses less digits than its factorization.

66681500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 903 (or 891 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 66681500 is about 8165.8741112021. The cubic root of 66681500 is about 405.5102039179.

The spelling of 66681500 in words is "sixty-six million, six hundred eighty-one thousand, five hundred".