6721040 has 40 divisors (see below), whose sum is σ = 16170840. Its totient is φ = 2594816.

The previous prime is 6721019. The next prime is 6721051. The reversal of 6721040 is 401276.

It can be written as a sum of positive squares in 4 ways, for example, as 85264 + 6635776 = 292^2 + 2576^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 872 + ... + 3768.

It is an arithmetic number, because the mean of its divisors is an integer number (404271).

Almost surely, 2^6721040 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 6721040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8085420).

6721040 is an abundant number, since it is smaller than the sum of its proper divisors (9449800).

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

6721040 is a wasteful number, since it uses less digits than its factorization.

6721040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2939 (or 2933 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 6721040 is about 2592.4968659576. The cubic root of 6721040 is about 188.7174936346.

The spelling of 6721040 in words is "six million, seven hundred twenty-one thousand, forty".