643741340 has 48 divisors (see below), whose sum is σ = 1478633184. Its totient is φ = 233472000.

The previous prime is 643741331. The next prime is 643741367. The reversal of 643741340 is 43147346.

It is a junction number, because it is equal to n+sod(n) for n = 643741297 and 643741306.

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 15 ways as a sum of consecutive naturals, for example, 84572 + ... + 91868.

It is an arithmetic number, because the mean of its divisors is an integer number (30804858).

Almost surely, 2^643741340 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643741340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (739316592).

643741340 is an abundant number, since it is smaller than the sum of its proper divisors (834891844).

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

643741340 is a wasteful number, since it uses less digits than its factorization.

643741340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7718 (or 7716 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 32.

The square root of 643741340 is about 25372.0582531256. The cubic root of 643741340 is about 863.4498795005.

Adding to 643741340 its reverse (43147346), we get a palindrome (686888686).

The spelling of 643741340 in words is "six hundred forty-three million, seven hundred forty-one thousand, three hundred forty".