66440403 has 24 divisors (see below), whose sum is σ = 102115728. Its totient is φ = 41482752.

The previous prime is 66440401. The next prime is 66440447. The reversal of 66440403 is 30404466.

It is a happy number.

It is not a de Polignac number, because 66440403 - 2¹ = 66440401 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66440401) 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 23 ways as a sum of consecutive naturals, for example, 33775 + ... + 35687.

It is an arithmetic number, because the mean of its divisors is an integer number (4254822).

Almost surely, 2^66440403 is an apocalyptic number.

66440403 is a deficient number, since it is larger than the sum of its proper divisors (35675325).

66440403 is a wasteful number, since it uses less digits than its factorization.

66440403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2163 (or 2160 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

The square root of 66440403 is about 8151.0982695585. The cubic root of 66440403 is about 405.0208859828.

Adding to 66440403 its reverse (30404466), we get a palindrome (96844869).

The spelling of 66440403 in words is "sixty-six million, four hundred forty thousand, four hundred three".