66440930 has 16 divisors (see below), whose sum is σ = 126628920. Its totient is φ = 25012992.

The previous prime is 66440921. The next prime is 66440953. The reversal of 66440930 is 3904466.

It can be written as a sum of positive squares in 4 ways, for example, as 59274601 + 7166329 = 7699^2 + 2677^2 .

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 7 ways as a sum of consecutive naturals, for example, 195245 + ... + 195584.

Almost surely, 2^66440930 is an apocalyptic number.

66440930 is a deficient number, since it is larger than the sum of its proper divisors (60187990).

66440930 is a wasteful number, since it uses less digits than its factorization.

66440930 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390853.

The product of its (nonzero) digits is 15552, while the sum is 32.

The square root of 66440930 is about 8151.1305964265. The cubic root of 66440930 is about 405.0219568445.

Subtracting from 66440930 its reverse (3904466), we obtain a square (62536464 = 7908²).

The spelling of 66440930 in words is "sixty-six million, four hundred forty thousand, nine hundred thirty".