8237721 has 4 divisors (see below), whose sum is σ = 10983632. Its totient is φ = 5491812.

The previous prime is 8237701. The next prime is 8237729. The reversal of 8237721 is 1277328.

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 not a de Polignac number, because 8237721 - 2¹¹ = 8235673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8237729) 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, 1372951 + ... + 1372956.

It is an arithmetic number, because the mean of its divisors is an integer number (2745908).

Almost surely, 2^8237721 is an apocalyptic number.

It is an amenable number.

8237721 is a deficient number, since it is larger than the sum of its proper divisors (2745911).

8237721 is a wasteful number, since it uses less digits than its factorization.

8237721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2745910.

The product of its digits is 4704, while the sum is 30.

The square root of 8237721 is about 2870.1430277950. The cubic root of 8237721 is about 201.9617040103.

The spelling of 8237721 in words is "eight million, two hundred thirty-seven thousand, seven hundred twenty-one".