66640002 has 64 divisors (see below), whose sum is σ = 158336640. Its totient is φ = 18432000.

The previous prime is 66639977. The next prime is 66640003. The reversal of 66640002 is 20004666.

66640002 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 (66640003) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 86274 + ... + 87042.

It is an arithmetic number, because the mean of its divisors is an integer number (2474010).

Almost surely, 2^66640002 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66640002, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79168320).

66640002 is an abundant number, since it is smaller than the sum of its proper divisors (91696638).

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

66640002 is a wasteful number, since it uses less digits than its factorization.

66640002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 899.

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 66640002 is about 8163.3327752824. The cubic root of 66640002 is about 405.4260658662.

Adding to 66640002 its reverse (20004666), we get a palindrome (86644668).

The spelling of 66640002 in words is "sixty-six million, six hundred forty thousand, two".