64640223 has 48 divisors (see below), whose sum is σ = 102960000. Its totient is φ = 38937024.

The previous prime is 64640209. The next prime is 64640227. The reversal of 64640223 is 32204646.

It is a de Polignac number, because none of the positive numbers 2^k-64640223 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64640227) 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 47 ways as a sum of consecutive naturals, for example, 433753 + ... + 433901.

It is an arithmetic number, because the mean of its divisors is an integer number (2145000).

Almost surely, 2^64640223 is an apocalyptic number.

64640223 is a deficient number, since it is larger than the sum of its proper divisors (38319777).

64640223 is a wasteful number, since it uses less digits than its factorization.

64640223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276 (or 273 counting only the distinct ones).

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

The square root of 64640223 is about 8039.9143652156. The cubic root of 64640223 is about 401.3293749280.

Adding to 64640223 its reverse (32204646), we get a palindrome (96844869).

The spelling of 64640223 in words is "sixty-four million, six hundred forty thousand, two hundred twenty-three".