643923983051 has 2 divisors, whose sum is σ = 643923983052. Its totient is φ = 643923983050.

The previous prime is 643923983047. The next prime is 643923983063. The reversal of 643923983051 is 150389329346.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 643923983051 - 2² = 643923983047 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 643923982984 and 643923983002.

It is not a weakly prime, because it can be changed into another prime (643923983251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321961991525 + 321961991526.

It is an arithmetic number, because the mean of its divisors is an integer number (321961991526).

Almost surely, 2^643923983051 is an apocalyptic number.

643923983051 is a deficient number, since it is larger than the sum of its proper divisors (1).

643923983051 is an equidigital number, since it uses as much as digits as its factorization.

643923983051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4199040, while the sum is 53.

The spelling of 643923983051 in words is "six hundred forty-three billion, nine hundred twenty-three million, nine hundred eighty-three thousand, fifty-one".