9991324787 has 2 divisors, whose sum is σ = 9991324788. Its totient is φ = 9991324786.

The previous prime is 9991324771. The next prime is 9991324801. The reversal of 9991324787 is 7874231999.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 9991324787 - 2⁴ = 9991324771 is a prime.

It is not a weakly prime, because it can be changed into another prime (9991324757) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4995662393 + 4995662394.

It is an arithmetic number, because the mean of its divisors is an integer number (4995662394).

Almost surely, 2^9991324787 is an apocalyptic number.

9991324787 is a deficient number, since it is larger than the sum of its proper divisors (1).

9991324787 is an equidigital number, since it uses as much as digits as its factorization.

9991324787 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6858432, while the sum is 59.

The square root of 9991324787 is about 99956.6145235021. The cubic root of 9991324787 is about 2153.8115037937.

The spelling of 9991324787 in words is "nine billion, nine hundred ninety-one million, three hundred twenty-four thousand, seven hundred eighty-seven".