643541197847 has 2 divisors, whose sum is σ = 643541197848. Its totient is φ = 643541197846.

The previous prime is 643541197801. The next prime is 643541197879. The reversal of 643541197847 is 748791145346.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 643541197847 - 2¹⁴ = 643541181463 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643541197547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321770598923 + 321770598924.

It is an arithmetic number, because the mean of its divisors is an integer number (321770598924).

Almost surely, 2^643541197847 is an apocalyptic number.

643541197847 is a deficient number, since it is larger than the sum of its proper divisors (1).

643541197847 is an equidigital number, since it uses as much as digits as its factorization.

643541197847 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20321280, while the sum is 59.

The spelling of 643541197847 in words is "six hundred forty-three billion, five hundred forty-one million, one hundred ninety-seven thousand, eight hundred forty-seven".