643451944227 has 8 divisors (see below), whose sum is σ = 858095207616. Its totient is φ = 428888321832.

The previous prime is 643451944207. The next prime is 643451944243. The reversal of 643451944227 is 722449154346.

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

It is not a de Polignac number, because 643451944227 - 2¹¹ = 643451942179 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 643451944227.

It is not an unprimeable number, because it can be changed into a prime (643451944207) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19891393 + ... + 19923714.

It is an arithmetic number, because the mean of its divisors is an integer number (107261900952).

Almost surely, 2^643451944227 is an apocalyptic number.

643451944227 is a deficient number, since it is larger than the sum of its proper divisors (214643263389).

643451944227 is a wasteful number, since it uses less digits than its factorization.

643451944227 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39820497.

The product of its digits is 5806080, while the sum is 51.

It can be divided in two parts, 6434519 and 44227, that added together give a palindrome (6478746).

The spelling of 643451944227 in words is "six hundred forty-three billion, four hundred fifty-one million, nine hundred forty-four thousand, two hundred twenty-seven".