6500721 has 8 divisors (see below), whose sum is σ = 8726400. Its totient is φ = 4304432.

The previous prime is 6500693. The next prime is 6500729. The reversal of 6500721 is 1270056.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6500721 - 2⁹ = 6500209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6500729) 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 7 ways as a sum of consecutive naturals, for example, 6825 + ... + 7718.

It is an arithmetic number, because the mean of its divisors is an integer number (1090800).

Almost surely, 2^6500721 is an apocalyptic number.

It is an amenable number.

6500721 is a deficient number, since it is larger than the sum of its proper divisors (2225679).

6500721 is a wasteful number, since it uses less digits than its factorization.

6500721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14695.

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 6500721 is about 2549.6511526089. The cubic root of 6500721 is about 186.6324579461.

Adding to 6500721 its reverse (1270056), we get a palindrome (7770777).

The spelling of 6500721 in words is "six million, five hundred thousand, seven hundred twenty-one".