8247991 has 2 divisors, whose sum is σ = 8247992. Its totient is φ = 8247990.

The previous prime is 8247973. The next prime is 8247997. The reversal of 8247991 is 1997428.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8247991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8247997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4123995 + 4123996.

It is an arithmetic number, because the mean of its divisors is an integer number (4123996).

Almost surely, 2^8247991 is an apocalyptic number.

8247991 is a deficient number, since it is larger than the sum of its proper divisors (1).

8247991 is an equidigital number, since it uses as much as digits as its factorization.

8247991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 40.

The square root of 8247991 is about 2871.9315799650. The cubic root of 8247991 is about 202.0455979800.

The spelling of 8247991 in words is "eight million, two hundred forty-seven thousand, nine hundred ninety-one".