643956127516 has 48 divisors (see below), whose sum is σ = 1285944271360. Its totient is φ = 279703108800.

The previous prime is 643956127513. The next prime is 643956127567. The reversal of 643956127516 is 615721659346.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643956127513) 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 15 ways as a sum of consecutive naturals, for example, 2009016 + ... + 2307391.

Almost surely, 2^643956127516 is an apocalyptic number.

It is an amenable number.

643956127516 is a deficient number, since it is larger than the sum of its proper divisors (641988143844).

643956127516 is a wasteful number, since it uses less digits than its factorization.

643956127516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4316594 (or 4316592 counting only the distinct ones).

The product of its digits is 8164800, while the sum is 55.

The spelling of 643956127516 in words is "six hundred forty-three billion, nine hundred fifty-six million, one hundred twenty-seven thousand, five hundred sixteen".