640632443 has 24 divisors (see below), whose sum is σ = 753950400. Its totient is φ = 542274480.

The previous prime is 640632407. The next prime is 640632457. The reversal of 640632443 is 344236046.

It is not a de Polignac number, because 640632443 - 2¹⁶ = 640566907 is a prime.

It is not an unprimeable number, because it can be changed into a prime (640632463) 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, 133280 + ... + 138002.

It is an arithmetic number, because the mean of its divisors is an integer number (31414600).

Almost surely, 2^640632443 is an apocalyptic number.

640632443 is a deficient number, since it is larger than the sum of its proper divisors (113317957).

640632443 is a wasteful number, since it uses less digits than its factorization.

640632443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4823 (or 4812 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 32.

The square root of 640632443 is about 25310.7179471464. The cubic root of 640632443 is about 862.0576486299.

Adding to 640632443 its reverse (344236046), we get a palindrome (984868489).

The spelling of 640632443 in words is "six hundred forty million, six hundred thirty-two thousand, four hundred forty-three".