643845726511 has 16 divisors (see below), whose sum is σ = 723789513216. Its totient is φ = 568266579936.

The previous prime is 643845726481. The next prime is 643845726541. The reversal of 643845726511 is 115627548346.

It is an interprime number because it is at equal distance from previous prime (643845726481) and next prime (643845726541).

It is a cyclic number.

It is not a de Polignac number, because 643845726511 - 2¹³ = 643845718319 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643845726541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 400926 + ... + 1203508.

It is an arithmetic number, because the mean of its divisors is an integer number (45236844576).

Almost surely, 2^643845726511 is an apocalyptic number.

643845726511 is a deficient number, since it is larger than the sum of its proper divisors (79943786705).

643845726511 is a wasteful number, since it uses less digits than its factorization.

643845726511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 805302.

The product of its digits is 4838400, while the sum is 52.

The spelling of 643845726511 in words is "six hundred forty-three billion, eight hundred forty-five million, seven hundred twenty-six thousand, five hundred eleven".