8123721 has 8 divisors (see below), whose sum is σ = 10845120. Its totient is φ = 5409072.

The previous prime is 8123719. The next prime is 8123729. The reversal of 8123721 is 1273218.

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

It is not a de Polignac number, because 8123721 - 2¹ = 8123719 is a prime.

It is a Curzon number.

It is a plaindrome in base 14.

It is a junction number, because it is equal to n+sod(n) for n = 8123691 and 8123700.

It is not an unprimeable number, because it can be changed into a prime (8123729) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2931 + ... + 4983.

It is an arithmetic number, because the mean of its divisors is an integer number (1355640).

Almost surely, 2^8123721 is an apocalyptic number.

It is an amenable number.

8123721 is a deficient number, since it is larger than the sum of its proper divisors (2721399).

8123721 is a wasteful number, since it uses less digits than its factorization.

8123721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3375.

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

The square root of 8123721 is about 2850.2142024767. The cubic root of 8123721 is about 201.0257386410.

Adding to 8123721 its reverse (1273218), we get a palindrome (9396939).

The spelling of 8123721 in words is "eight million, one hundred twenty-three thousand, seven hundred twenty-one".