66890000 has 50 divisors (see below), whose sum is σ = 161971590. Its totient is φ = 26752000.

The previous prime is 66889993. The next prime is 66890017. The reversal of 66890000 is 9866.

66890000 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 14992384 + 51897616 = 3872^2 + 7204^2 .

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

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, 6656 + ... + 13344.

Almost surely, 2^66890000 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 66890000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80985795).

66890000 is an abundant number, since it is smaller than the sum of its proper divisors (95081590).

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

66890000 is an equidigital number, since it uses as much as digits as its factorization.

66890000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6717 (or 6696 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 66890000 is about 8178.6306922369. The cubic root of 66890000 is about 405.9324145145.

Adding to 66890000 its reverse (9866), we get a palindrome (66899866).

The spelling of 66890000 in words is "sixty-six million, eight hundred ninety thousand".