643946303 has 16 divisors (see below), whose sum is σ = 864600576. Its totient is φ = 463177440.

The previous prime is 643946299. The next prime is 643946323. The reversal of 643946303 is 303649346.

It is not a de Polignac number, because 643946303 - 2² = 643946299 is a prime.

It is a super-2 number, since 2×643946303² = 829333682294735618, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643946323) 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, 320651 + ... + 322652.

It is an arithmetic number, because the mean of its divisors is an integer number (54037536).

Almost surely, 2^643946303 is an apocalyptic number.

643946303 is a deficient number, since it is larger than the sum of its proper divisors (220654273).

643946303 is a wasteful number, since it uses less digits than its factorization.

643946303 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643334.

The product of its (nonzero) digits is 139968, while the sum is 38.

The square root of 643946303 is about 25376.0970797323. The cubic root of 643946303 is about 863.5415086935.

The spelling of 643946303 in words is "six hundred forty-three million, nine hundred forty-six thousand, three hundred three".