643358273 has 2 divisors, whose sum is σ = 643358274. Its totient is φ = 643358272.

The previous prime is 643358263. The next prime is 643358281. The reversal of 643358273 is 372853346.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 472062529 + 171295744 = 21727^2 + 13088^2 .

It is a cyclic number.

It is not a de Polignac number, because 643358273 - 2¹² = 643354177 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 643358273.

It is not a weakly prime, because it can be changed into another prime (643358213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321679136 + 321679137.

It is an arithmetic number, because the mean of its divisors is an integer number (321679137).

Almost surely, 2^643358273 is an apocalyptic number.

It is an amenable number.

643358273 is a deficient number, since it is larger than the sum of its proper divisors (1).

643358273 is an equidigital number, since it uses as much as digits as its factorization.

643358273 is an evil number, because the sum of its binary digits is even.

The product of its digits is 362880, while the sum is 41.

The square root of 643358273 is about 25364.5081363704. The cubic root of 643358273 is about 863.2785763369.

The spelling of 643358273 in words is "six hundred forty-three million, three hundred fifty-eight thousand, two hundred seventy-three".