643792673 has 2 divisors, whose sum is σ = 643792674. Its totient is φ = 643792672.

The previous prime is 643792631. The next prime is 643792679. The reversal of 643792673 is 376297346.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 643738384 + 54289 = 25372^2 + 233^2 .

It is a cyclic number.

It is not a de Polignac number, because 643792673 - 2¹² = 643788577 is a prime.

It is not a weakly prime, because it can be changed into another prime (643792679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321896336 + 321896337.

It is an arithmetic number, because the mean of its divisors is an integer number (321896337).

Almost surely, 2^643792673 is an apocalyptic number.

It is an amenable number.

643792673 is a deficient number, since it is larger than the sum of its proper divisors (1).

643792673 is an equidigital number, since it uses as much as digits as its factorization.

643792673 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1143072, while the sum is 47.

The square root of 643792673 is about 25373.0698379207. The cubic root of 643792673 is about 863.4728298647.

The spelling of 643792673 in words is "six hundred forty-three million, seven hundred ninety-two thousand, six hundred seventy-three".