8006721 has 4 divisors (see below), whose sum is σ = 10675632. Its totient is φ = 5337812.

The previous prime is 8006699. The next prime is 8006749. The reversal of 8006721 is 1276008.

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 8006721 - 2⁹ = 8006209 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 8006691 and 8006700.

It is not an unprimeable number, because it can be changed into a prime (8006221) 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, 1334451 + ... + 1334456.

It is an arithmetic number, because the mean of its divisors is an integer number (2668908).

Almost surely, 2^8006721 is an apocalyptic number.

It is an amenable number.

8006721 is a deficient number, since it is larger than the sum of its proper divisors (2668911).

8006721 is a wasteful number, since it uses less digits than its factorization.

8006721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2668910.

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 8006721 is about 2829.6149914785. The cubic root of 8006721 is about 200.0559926560.

The spelling of 8006721 in words is "eight million, six thousand, seven hundred twenty-one".