66610000 has 50 divisors (see below), whose sum is σ = 161293682. Its totient is φ = 26640000.

The previous prime is 66609989. The next prime is 66610021. The reversal of 66610000 is 1666.

It is a happy number.

66610000 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 5 ways, for example, as 10419984 + 56190016 = 3228^2 + 7496^2 .

It is a tau number, because it is divible by the number of its divisors (50).

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 66610000.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 6670 + ... + 13330.

Almost surely, 2^66610000 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 66610000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80646841).

66610000 is an abundant number, since it is smaller than the sum of its proper divisors (94683682).

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

66610000 is an equidigital number, since it uses as much as digits as its factorization.

66610000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6689 (or 6668 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 66610000 is about 8161.4949610963. The cubic root of 66610000 is about 405.3652144341.

Adding to 66610000 its reverse (1666), we get a palindrome (66611666).

The spelling of 66610000 in words is "sixty-six million, six hundred ten thousand".