643354561867 has 2 divisors, whose sum is σ = 643354561868. Its totient is φ = 643354561866.

The previous prime is 643354561807. The next prime is 643354561937. The reversal of 643354561867 is 768165453346.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 643354561867 - 2⁷ = 643354561739 is a prime.

It is not a weakly prime, because it can be changed into another prime (643354561807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321677280933 + 321677280934.

It is an arithmetic number, because the mean of its divisors is an integer number (321677280934).

Almost surely, 2^643354561867 is an apocalyptic number.

643354561867 is a deficient number, since it is larger than the sum of its proper divisors (1).

643354561867 is an equidigital number, since it uses as much as digits as its factorization.

643354561867 is an evil number, because the sum of its binary digits is even.

The product of its digits is 43545600, while the sum is 58.

The spelling of 643354561867 in words is "six hundred forty-three billion, three hundred fifty-four million, five hundred sixty-one thousand, eight hundred sixty-seven".