8668001721 has 4 divisors (see below), whose sum is σ = 11557335632. Its totient is φ = 5778667812.

The previous prime is 8668001711. The next prime is 8668001731. The reversal of 8668001721 is 1271008668.

8668001721 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 an interprime number because it is at equal distance from previous prime (8668001711) and next prime (8668001731).

It is not a de Polignac number, because 8668001721 - 2²³ = 8659613113 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 8668001721.

It is not an unprimeable number, because it can be changed into a prime (8668001711) 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, 1444666951 + ... + 1444666956.

It is an arithmetic number, because the mean of its divisors is an integer number (2889333908).

Almost surely, 2^8668001721 is an apocalyptic number.

It is an amenable number.

8668001721 is a deficient number, since it is larger than the sum of its proper divisors (2889333911).

8668001721 is a wasteful number, since it uses less digits than its factorization.

8668001721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2889333910.

The product of its (nonzero) digits is 32256, while the sum is 39.

The square root of 8668001721 is about 93102.1037410004. The cubic root of 8668001721 is about 2054.1855172370.

The spelling of 8668001721 in words is "eight billion, six hundred sixty-eight million, one thousand, seven hundred twenty-one".