9991324751 has 2 divisors, whose sum is σ = 9991324752. Its totient is φ = 9991324750.

The previous prime is 9991324703. The next prime is 9991324753. The reversal of 9991324751 is 1574231999.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 9991324751 - 2⁶ = 9991324687 is a prime.

It is a Sophie Germain prime.

Together with 9991324753, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 9991324751.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9991324753) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4995662375 + 4995662376.

It is an arithmetic number, because the mean of its divisors is an integer number (4995662376).

Almost surely, 2^9991324751 is an apocalyptic number.

9991324751 is a deficient number, since it is larger than the sum of its proper divisors (1).

9991324751 is an equidigital number, since it uses as much as digits as its factorization.

9991324751 is an evil number, because the sum of its binary digits is even.

The product of its digits is 612360, while the sum is 50.

The square root of 9991324751 is about 99956.6143434240. The cubic root of 9991324751 is about 2153.8115012068.

The spelling of 9991324751 in words is "nine billion, nine hundred ninety-one million, three hundred twenty-four thousand, seven hundred fifty-one".