643773041 has 2 divisors, whose sum is σ = 643773042. Its totient is φ = 643773040.

The previous prime is 643772993. The next prime is 643773073. The reversal of 643773041 is 140377346.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 634032400 + 9740641 = 25180^2 + 3121^2 .

It is a cyclic number.

It is not a de Polignac number, because 643773041 - 2⁶ = 643772977 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 643772992 and 643773010.

It is not a weakly prime, because it can be changed into another prime (643779041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321886520 + 321886521.

It is an arithmetic number, because the mean of its divisors is an integer number (321886521).

Almost surely, 2^643773041 is an apocalyptic number.

It is an amenable number.

643773041 is a deficient number, since it is larger than the sum of its proper divisors (1).

643773041 is an equidigital number, since it uses as much as digits as its factorization.

643773041 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 42336, while the sum is 35.

The square root of 643773041 is about 25372.6829681057. The cubic root of 643773041 is about 863.4640527787.

The spelling of 643773041 in words is "six hundred forty-three million, seven hundred seventy-three thousand, forty-one".