643883 has 2 divisors, whose sum is σ = 643884. Its totient is φ = 643882.

The previous prime is 643879. The next prime is 643889. The reversal of 643883 is 388346.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 643883 - 2² = 643879 is a prime.

It is a super-3 number, since 3×643883³ = 800833314328639161, which contains 333 as substring.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (643889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321941 + 321942.

It is an arithmetic number, because the mean of its divisors is an integer number (321942).

2⁶⁴³⁸⁸³ is an apocalyptic number.

643883 is a deficient number, since it is larger than the sum of its proper divisors (1).

643883 is an equidigital number, since it uses as much as digits as its factorization.

643883 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13824, while the sum is 32.

The square root of 643883 is about 802.4232050483. The cubic root of 643883 is about 86.3513211013.

The spelling of 643883 in words is "six hundred forty-three thousand, eight hundred eighty-three".