8239921 has 2 divisors, whose sum is σ = 8239922. Its totient is φ = 8239920.

The previous prime is 8239879. The next prime is 8239927. The reversal of 8239921 is 1299328.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5880625 + 2359296 = 2425^2 + 1536^2 .

It is a cyclic number.

It is not a de Polignac number, because 8239921 - 2¹⁵ = 8207153 is a prime.

It is not a weakly prime, because it can be changed into another prime (8239927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4119960 + 4119961.

It is an arithmetic number, because the mean of its divisors is an integer number (4119961).

Almost surely, 2^8239921 is an apocalyptic number.

It is an amenable number.

8239921 is a deficient number, since it is larger than the sum of its proper divisors (1).

8239921 is an equidigital number, since it uses as much as digits as its factorization.

8239921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 34.

The square root of 8239921 is about 2870.5262583715. The cubic root of 8239921 is about 201.9796813206.

The spelling of 8239921 in words is "eight million, two hundred thirty-nine thousand, nine hundred twenty-one".