6640223186 has 4 divisors (see below), whose sum is σ = 9960334782. Its totient is φ = 3320111592.

The previous prime is 6640223159. The next prime is 6640223209. The reversal of 6640223186 is 6813220466.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 4048904161 + 2591319025 = 63631^2 + 50905^2 .

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 as a sum of consecutive naturals, namely, 1660055795 + ... + 1660055798.

Almost surely, 2^6640223186 is an apocalyptic number.

6640223186 is a deficient number, since it is larger than the sum of its proper divisors (3320111596).

6640223186 is a wasteful number, since it uses less digits than its factorization.

6640223186 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3320111595.

The product of its (nonzero) digits is 82944, while the sum is 38.

The square root of 6640223186 is about 81487.5646095771. The cubic root of 6640223186 is about 1879.5803335557.

The spelling of 6640223186 in words is "six billion, six hundred forty million, two hundred twenty-three thousand, one hundred eighty-six".