643456814 has 64 divisors (see below), whose sum is σ = 1340720640. Its totient is φ = 223413120.

The previous prime is 643456769. The next prime is 643456819. The reversal of 643456814 is 418654346.

It is a happy number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643456819) 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 31 ways as a sum of consecutive naturals, for example, 52517 + ... + 63599.

It is an arithmetic number, because the mean of its divisors is an integer number (20948760).

Almost surely, 2^643456814 is an apocalyptic number.

643456814 is an abundant number, since it is smaller than the sum of its proper divisors (697263826).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643456814 is a wasteful number, since it uses less digits than its factorization.

643456814 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11145.

The product of its digits is 276480, while the sum is 41.

The square root of 643456814 is about 25366.4505597452. The cubic root of 643456814 is about 863.3226492353.

The spelling of 643456814 in words is "six hundred forty-three million, four hundred fifty-six thousand, eight hundred fourteen".