640632323 has 8 divisors (see below), whose sum is σ = 647086080. Its totient is φ = 634200840.

The previous prime is 640632287. The next prime is 640632337. The reversal of 640632323 is 323236046.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 640632323 - 2⁸ = 640632067 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640632373) 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 7 ways as a sum of consecutive naturals, for example, 55568 + ... + 66098.

It is an arithmetic number, because the mean of its divisors is an integer number (80885760).

Almost surely, 2^640632323 is an apocalyptic number.

640632323 is a deficient number, since it is larger than the sum of its proper divisors (6453757).

640632323 is a wasteful number, since it uses less digits than its factorization.

640632323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11137.

The product of its (nonzero) digits is 15552, while the sum is 29.

The square root of 640632323 is about 25310.7155766091. The cubic root of 640632323 is about 862.0575948044.

Adding to 640632323 its reverse (323236046), we get a palindrome (963868369).

The spelling of 640632323 in words is "six hundred forty million, six hundred thirty-two thousand, three hundred twenty-three".