643594447 has 2 divisors, whose sum is σ = 643594448. Its totient is φ = 643594446.

The previous prime is 643594421. The next prime is 643594463. The reversal of 643594447 is 744495346.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 643594447 - 2⁷ = 643594319 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 643594397 and 643594406.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643504447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321797223 + 321797224.

It is an arithmetic number, because the mean of its divisors is an integer number (321797224).

Almost surely, 2^643594447 is an apocalyptic number.

643594447 is a deficient number, since it is larger than the sum of its proper divisors (1).

643594447 is an equidigital number, since it uses as much as digits as its factorization.

643594447 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1451520, while the sum is 46.

The square root of 643594447 is about 25369.1633090254. The cubic root of 643594447 is about 863.3841986730.

It can be divided in two parts, 6 and 43594447, that added together give a triangular number (43594453 = T₉₃₃₇).

The spelling of 643594447 in words is "six hundred forty-three million, five hundred ninety-four thousand, four hundred forty-seven".