643845726510 has 128 divisors (see below), whose sum is σ = 1880190434304. Its totient is φ = 137742612480.

The previous prime is 643845726481. The next prime is 643845726541. The reversal of 643845726510 is 15627548346.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 147969 + ... + 1144371.

It is an arithmetic number, because the mean of its divisors is an integer number (14688987768).

Almost surely, 2^643845726510 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643845726510, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (940095217152).

643845726510 is an abundant number, since it is smaller than the sum of its proper divisors (1236344707794).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643845726510 is a wasteful number, since it uses less digits than its factorization.

643845726510 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 996618.

The product of its (nonzero) digits is 4838400, while the sum is 51.

The spelling of 643845726510 in words is "six hundred forty-three billion, eight hundred forty-five million, seven hundred twenty-six thousand, five hundred ten".