6328721 has 4 divisors (see below), whose sum is σ = 7232832. Its totient is φ = 5424612.

The previous prime is 6328711. The next prime is 6328723. The reversal of 6328721 is 1278236.

It is a happy number.

6328721 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6328721 - 2²² = 2134417 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6328723) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 452045 + ... + 452058.

It is an arithmetic number, because the mean of its divisors is an integer number (1808208).

Almost surely, 2^6328721 is an apocalyptic number.

It is an amenable number.

6328721 is a deficient number, since it is larger than the sum of its proper divisors (904111).

6328721 is an equidigital number, since it uses as much as digits as its factorization.

6328721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 904110.

The product of its digits is 4032, while the sum is 29.

The square root of 6328721 is about 2515.6949338105. The cubic root of 6328721 is about 184.9717122563.

The spelling of 6328721 in words is "six million, three hundred twenty-eight thousand, seven hundred twenty-one".