8111721 has 4 divisors (see below), whose sum is σ = 10815632. Its totient is φ = 5407812.

The previous prime is 8111717. The next prime is 8111723. The reversal of 8111721 is 1271118.

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 8111721 - 2² = 8111717 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (8111723) 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, 1351951 + ... + 1351956.

It is an arithmetic number, because the mean of its divisors is an integer number (2703908).

Almost surely, 2^8111721 is an apocalyptic number.

It is an amenable number.

8111721 is a deficient number, since it is larger than the sum of its proper divisors (2703911).

8111721 is a wasteful number, since it uses less digits than its factorization.

8111721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2703910.

The product of its digits is 112, while the sum is 21.

The square root of 8111721 is about 2848.1083195693. The cubic root of 8111721 is about 200.9267077649.

Adding to 8111721 its reverse (1271118), we get a palindrome (9382839).

The spelling of 8111721 in words is "eight million, one hundred eleven thousand, seven hundred twenty-one".