643391431671 has 8 divisors (see below), whose sum is σ = 857860872064. Its totient is φ = 428924806200.

The previous prime is 643391431643. The next prime is 643391431691. The reversal of 643391431671 is 176134193346.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 643391431671 - 2⁹ = 643391431159 is a prime.

It is a super-3 number, since 3×643391431671³ (a number of 36 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 643391431671.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643391431691) 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 in 7 ways as a sum of consecutive naturals, for example, 95251 + ... + 1138356.

It is an arithmetic number, because the mean of its divisors is an integer number (107232609008).

Almost surely, 2^643391431671 is an apocalyptic number.

643391431671 is a deficient number, since it is larger than the sum of its proper divisors (214469440393).

643391431671 is a wasteful number, since it uses less digits than its factorization.

643391431671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1407461.

The product of its digits is 979776, while the sum is 48.

The spelling of 643391431671 in words is "six hundred forty-three billion, three hundred ninety-one million, four hundred thirty-one thousand, six hundred seventy-one".