643681303 has 16 divisors (see below), whose sum is σ = 689045760. Its totient is φ = 599961600.

The previous prime is 643681279. The next prime is 643681397. The reversal of 643681303 is 303186346.

It is not a de Polignac number, because 643681303 - 2⁵ = 643681271 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643681603) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 575701 + ... + 576817.

It is an arithmetic number, because the mean of its divisors is an integer number (43065360).

Almost surely, 2^643681303 is an apocalyptic number.

643681303 is a deficient number, since it is larger than the sum of its proper divisors (45364457).

643681303 is a wasteful number, since it uses less digits than its factorization.

643681303 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1818.

The product of its (nonzero) digits is 31104, while the sum is 34.

The square root of 643681303 is about 25370.8750933033. The cubic root of 643681303 is about 863.4230361351.

The spelling of 643681303 in words is "six hundred forty-three million, six hundred eighty-one thousand, three hundred three".