6721618240 has 28 divisors (see below), whose sum is σ = 16005854196. Its totient is φ = 2688647168.

The previous prime is 6721618223. The next prime is 6721618249. The reversal of 6721618240 is 428161276.

It can be written as a sum of positive squares in 2 ways, for example, as 4381380864 + 2340237376 = 66192^2 + 48376^2 .

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 6721618240.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6721618249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10502209 + ... + 10502848.

Almost surely, 2^6721618240 is an apocalyptic number.

It is an amenable number.

6721618240 is an abundant number, since it is smaller than the sum of its proper divisors (9284235956).

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

6721618240 is a wasteful number, since it uses less digits than its factorization.

6721618240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21005074 (or 21005064 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 37.

The square root of 6721618240 is about 81985.4757868734. The cubic root of 6721618240 is about 1887.2290553881.

The spelling of 6721618240 in words is "six billion, seven hundred twenty-one million, six hundred eighteen thousand, two hundred forty".