643776677629 has 2 divisors, whose sum is σ = 643776677630. Its totient is φ = 643776677628.

The previous prime is 643776677603. The next prime is 643776677639. The reversal of 643776677629 is 926776677346.

643776677629 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 629010782404 + 14765895225 = 793102^2 + 121515^2 .

It is a cyclic number.

It is not a de Polignac number, because 643776677629 - 2⁵ = 643776677597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643776677639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321888338814 + 321888338815.

It is an arithmetic number, because the mean of its divisors is an integer number (321888338815).

Almost surely, 2^643776677629 is an apocalyptic number.

It is an amenable number.

643776677629 is a deficient number, since it is larger than the sum of its proper divisors (1).

643776677629 is an equidigital number, since it uses as much as digits as its factorization.

643776677629 is an evil number, because the sum of its binary digits is even.

The product of its digits is 672126336, while the sum is 70.

The spelling of 643776677629 in words is "six hundred forty-three billion, seven hundred seventy-six million, six hundred seventy-seven thousand, six hundred twenty-nine".