643254126538 has 8 divisors (see below), whose sum is σ = 974434469220. Its totient is φ = 318442636800.

The previous prime is 643254126509. The next prime is 643254126547. The reversal of 643254126538 is 835621452346.

It can be written as a sum of positive squares in 2 ways, for example, as 562849554289 + 80404572249 = 750233^2 + 283557^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 643254126491 and 643254126500.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1592212983 + ... + 1592213386.

Almost surely, 2^643254126538 is an apocalyptic number.

643254126538 is a deficient number, since it is larger than the sum of its proper divisors (331180342682).

643254126538 is a wasteful number, since it uses less digits than its factorization.

643254126538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3184426472.

The product of its digits is 4147200, while the sum is 49.

The spelling of 643254126538 in words is "six hundred forty-three billion, two hundred fifty-four million, one hundred twenty-six thousand, five hundred thirty-eight".