641789831 has 4 divisors (see below), whose sum is σ = 679542192. Its totient is φ = 604037472.

The previous prime is 641789821. The next prime is 641789833. The reversal of 641789831 is 138987146.

641789831 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 138987146 = 2 ⋅69493573.

It is not a de Polignac number, because 641789831 - 2⁶ = 641789767 is a prime.

It is a super-3 number, since 3×641789831³ (a number of 27 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641789833) 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, 18876155 + ... + 18876188.

It is an arithmetic number, because the mean of its divisors is an integer number (169885548).

Almost surely, 2^641789831 is an apocalyptic number.

641789831 is a deficient number, since it is larger than the sum of its proper divisors (37752361).

641789831 is a wasteful number, since it uses less digits than its factorization.

641789831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37752360.

The product of its digits is 290304, while the sum is 47.

The square root of 641789831 is about 25333.5712247602. The cubic root of 641789831 is about 862.5764770386.

The spelling of 641789831 in words is "six hundred forty-one million, seven hundred eighty-nine thousand, eight hundred thirty-one".