643543678389 has 4 divisors (see below), whose sum is σ = 858058237856. Its totient is φ = 429029118924.

The previous prime is 643543678361. The next prime is 643543678391. The reversal of 643543678389 is 983876345346.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 643543678389 - 2¹³ = 643543670197 is a prime.

It is a super-3 number, since 3×643543678389³ (a number of 36 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643543678399) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107257279729 + ... + 107257279734.

It is an arithmetic number, because the mean of its divisors is an integer number (214514559464).

Almost surely, 2^643543678389 is an apocalyptic number.

It is an amenable number.

643543678389 is a deficient number, since it is larger than the sum of its proper divisors (214514559467).

643543678389 is a wasteful number, since it uses less digits than its factorization.

643543678389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214514559466.

The product of its digits is 313528320, while the sum is 66.

The spelling of 643543678389 in words is "six hundred forty-three billion, five hundred forty-three million, six hundred seventy-eight thousand, three hundred eighty-nine".