643357973 has 16 divisors (see below), whose sum is σ = 671655936. Its totient is φ = 615582720.

The previous prime is 643357951. The next prime is 643357987. The reversal of 643357973 is 379753346.

643357973 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 643357973 - 2¹⁶ = 643292437 is a prime.

It is a Smith number, since the sum of its digits (47) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643357933) 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, 1752836 + ... + 1753202.

It is an arithmetic number, because the mean of its divisors is an integer number (41978496).

Almost surely, 2^643357973 is an apocalyptic number.

It is an amenable number.

643357973 is a deficient number, since it is larger than the sum of its proper divisors (28297963).

643357973 is a wasteful number, since it uses less digits than its factorization.

643357973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 884.

The product of its digits is 1428840, while the sum is 47.

The square root of 643357973 is about 25364.5022225945. The cubic root of 643357973 is about 863.2784421537.

The spelling of 643357973 in words is "six hundred forty-three million, three hundred fifty-seven thousand, nine hundred seventy-three".